a geicko-2 based round robin ranking system designed to test c++ battleship submissions
battleship.dunkirk.sh
dunkirk.sh
1#ifndef USE_LIBSQLITE3
2/*
3** 2001-09-15
4**
5** The author disclaims copyright to this source code. In place of
6** a legal notice, here is a blessing:
7**
8** May you do good and not evil.
9** May you find forgiveness for yourself and forgive others.
10** May you share freely, never taking more than you give.
11**
12*************************************************************************
13** This header file defines the interface that the SQLite library
14** presents to client programs. If a C-function, structure, datatype,
15** or constant definition does not appear in this file, then it is
16** not a published API of SQLite, is subject to change without
17** notice, and should not be referenced by programs that use SQLite.
18**
19** Some of the definitions that are in this file are marked as
20** "experimental". Experimental interfaces are normally new
21** features recently added to SQLite. We do not anticipate changes
22** to experimental interfaces but reserve the right to make minor changes
23** if experience from use "in the wild" suggest such changes are prudent.
24**
25** The official C-language API documentation for SQLite is derived
26** from comments in this file. This file is the authoritative source
27** on how SQLite interfaces are supposed to operate.
28**
29** The name of this file under configuration management is "sqlite.h.in".
30** The makefile makes some minor changes to this file (such as inserting
31** the version number) and changes its name to "sqlite3.h" as
32** part of the build process.
33*/
34#ifndef SQLITE3_H
35#define SQLITE3_H
36#include <stdarg.h> /* Needed for the definition of va_list */
37
38/*
39** Make sure we can call this stuff from C++.
40*/
41#ifdef __cplusplus
42extern "C" {
43#endif
44
45
46/*
47** Facilitate override of interface linkage and calling conventions.
48** Be aware that these macros may not be used within this particular
49** translation of the amalgamation and its associated header file.
50**
51** The SQLITE_EXTERN and SQLITE_API macros are used to instruct the
52** compiler that the target identifier should have external linkage.
53**
54** The SQLITE_CDECL macro is used to set the calling convention for
55** public functions that accept a variable number of arguments.
56**
57** The SQLITE_APICALL macro is used to set the calling convention for
58** public functions that accept a fixed number of arguments.
59**
60** The SQLITE_STDCALL macro is no longer used and is now deprecated.
61**
62** The SQLITE_CALLBACK macro is used to set the calling convention for
63** function pointers.
64**
65** The SQLITE_SYSAPI macro is used to set the calling convention for
66** functions provided by the operating system.
67**
68** Currently, the SQLITE_CDECL, SQLITE_APICALL, SQLITE_CALLBACK, and
69** SQLITE_SYSAPI macros are used only when building for environments
70** that require non-default calling conventions.
71*/
72#ifndef SQLITE_EXTERN
73# define SQLITE_EXTERN extern
74#endif
75#ifndef SQLITE_API
76# define SQLITE_API
77#endif
78#ifndef SQLITE_CDECL
79# define SQLITE_CDECL
80#endif
81#ifndef SQLITE_APICALL
82# define SQLITE_APICALL
83#endif
84#ifndef SQLITE_STDCALL
85# define SQLITE_STDCALL SQLITE_APICALL
86#endif
87#ifndef SQLITE_CALLBACK
88# define SQLITE_CALLBACK
89#endif
90#ifndef SQLITE_SYSAPI
91# define SQLITE_SYSAPI
92#endif
93
94/*
95** These no-op macros are used in front of interfaces to mark those
96** interfaces as either deprecated or experimental. New applications
97** should not use deprecated interfaces - they are supported for backwards
98** compatibility only. Application writers should be aware that
99** experimental interfaces are subject to change in point releases.
100**
101** These macros used to resolve to various kinds of compiler magic that
102** would generate warning messages when they were used. But that
103** compiler magic ended up generating such a flurry of bug reports
104** that we have taken it all out and gone back to using simple
105** noop macros.
106*/
107#define SQLITE_DEPRECATED
108#define SQLITE_EXPERIMENTAL
109
110/*
111** Ensure these symbols were not defined by some previous header file.
112*/
113#ifdef SQLITE_VERSION
114# undef SQLITE_VERSION
115#endif
116#ifdef SQLITE_VERSION_NUMBER
117# undef SQLITE_VERSION_NUMBER
118#endif
119
120/*
121** CAPI3REF: Compile-Time Library Version Numbers
122**
123** ^(The [SQLITE_VERSION] C preprocessor macro in the sqlite3.h header
124** evaluates to a string literal that is the SQLite version in the
125** format "X.Y.Z" where X is the major version number (always 3 for
126** SQLite3) and Y is the minor version number and Z is the release number.)^
127** ^(The [SQLITE_VERSION_NUMBER] C preprocessor macro resolves to an integer
128** with the value (X*1000000 + Y*1000 + Z) where X, Y, and Z are the same
129** numbers used in [SQLITE_VERSION].)^
130** The SQLITE_VERSION_NUMBER for any given release of SQLite will also
131** be larger than the release from which it is derived. Either Y will
132** be held constant and Z will be incremented or else Y will be incremented
133** and Z will be reset to zero.
134**
135** Since [version 3.6.18] ([dateof:3.6.18]),
136** SQLite source code has been stored in the
137** <a href="http://fossil-scm.org/">Fossil configuration management
138** system</a>. ^The SQLITE_SOURCE_ID macro evaluates to
139** a string which identifies a particular check-in of SQLite
140** within its configuration management system. ^The SQLITE_SOURCE_ID
141** string contains the date and time of the check-in (UTC) and a SHA1
142** or SHA3-256 hash of the entire source tree. If the source code has
143** been edited in any way since it was last checked in, then the last
144** four hexadecimal digits of the hash may be modified.
145**
146** See also: [sqlite3_libversion()],
147** [sqlite3_libversion_number()], [sqlite3_sourceid()],
148** [sqlite_version()] and [sqlite_source_id()].
149*/
150#define SQLITE_VERSION "3.50.4"
151#define SQLITE_VERSION_NUMBER 3050004
152#define SQLITE_SOURCE_ID "2025-07-30 19:33:53 4d8adfb30e03f9cf27f800a2c1ba3c48fb4ca1b08b0f5ed59a4d5ecbf45e20a3"
153
154/*
155** CAPI3REF: Run-Time Library Version Numbers
156** KEYWORDS: sqlite3_version sqlite3_sourceid
157**
158** These interfaces provide the same information as the [SQLITE_VERSION],
159** [SQLITE_VERSION_NUMBER], and [SQLITE_SOURCE_ID] C preprocessor macros
160** but are associated with the library instead of the header file. ^(Cautious
161** programmers might include assert() statements in their application to
162** verify that values returned by these interfaces match the macros in
163** the header, and thus ensure that the application is
164** compiled with matching library and header files.
165**
166** <blockquote><pre>
167** assert( sqlite3_libversion_number()==SQLITE_VERSION_NUMBER );
168** assert( strncmp(sqlite3_sourceid(),SQLITE_SOURCE_ID,80)==0 );
169** assert( strcmp(sqlite3_libversion(),SQLITE_VERSION)==0 );
170** </pre></blockquote>)^
171**
172** ^The sqlite3_version[] string constant contains the text of [SQLITE_VERSION]
173** macro. ^The sqlite3_libversion() function returns a pointer to the
174** to the sqlite3_version[] string constant. The sqlite3_libversion()
175** function is provided for use in DLLs since DLL users usually do not have
176** direct access to string constants within the DLL. ^The
177** sqlite3_libversion_number() function returns an integer equal to
178** [SQLITE_VERSION_NUMBER]. ^(The sqlite3_sourceid() function returns
179** a pointer to a string constant whose value is the same as the
180** [SQLITE_SOURCE_ID] C preprocessor macro. Except if SQLite is built
181** using an edited copy of [the amalgamation], then the last four characters
182** of the hash might be different from [SQLITE_SOURCE_ID].)^
183**
184** See also: [sqlite_version()] and [sqlite_source_id()].
185*/
186SQLITE_API SQLITE_EXTERN const char sqlite3_version[];
187SQLITE_API const char *sqlite3_libversion(void);
188SQLITE_API const char *sqlite3_sourceid(void);
189SQLITE_API int sqlite3_libversion_number(void);
190
191/*
192** CAPI3REF: Run-Time Library Compilation Options Diagnostics
193**
194** ^The sqlite3_compileoption_used() function returns 0 or 1
195** indicating whether the specified option was defined at
196** compile time. ^The SQLITE_ prefix may be omitted from the
197** option name passed to sqlite3_compileoption_used().
198**
199** ^The sqlite3_compileoption_get() function allows iterating
200** over the list of options that were defined at compile time by
201** returning the N-th compile time option string. ^If N is out of range,
202** sqlite3_compileoption_get() returns a NULL pointer. ^The SQLITE_
203** prefix is omitted from any strings returned by
204** sqlite3_compileoption_get().
205**
206** ^Support for the diagnostic functions sqlite3_compileoption_used()
207** and sqlite3_compileoption_get() may be omitted by specifying the
208** [SQLITE_OMIT_COMPILEOPTION_DIAGS] option at compile time.
209**
210** See also: SQL functions [sqlite_compileoption_used()] and
211** [sqlite_compileoption_get()] and the [compile_options pragma].
212*/
213#ifndef SQLITE_OMIT_COMPILEOPTION_DIAGS
214SQLITE_API int sqlite3_compileoption_used(const char *zOptName);
215SQLITE_API const char *sqlite3_compileoption_get(int N);
216#else
217# define sqlite3_compileoption_used(X) 0
218# define sqlite3_compileoption_get(X) ((void*)0)
219#endif
220
221/*
222** CAPI3REF: Test To See If The Library Is Threadsafe
223**
224** ^The sqlite3_threadsafe() function returns zero if and only if
225** SQLite was compiled with mutexing code omitted due to the
226** [SQLITE_THREADSAFE] compile-time option being set to 0.
227**
228** SQLite can be compiled with or without mutexes. When
229** the [SQLITE_THREADSAFE] C preprocessor macro is 1 or 2, mutexes
230** are enabled and SQLite is threadsafe. When the
231** [SQLITE_THREADSAFE] macro is 0,
232** the mutexes are omitted. Without the mutexes, it is not safe
233** to use SQLite concurrently from more than one thread.
234**
235** Enabling mutexes incurs a measurable performance penalty.
236** So if speed is of utmost importance, it makes sense to disable
237** the mutexes. But for maximum safety, mutexes should be enabled.
238** ^The default behavior is for mutexes to be enabled.
239**
240** This interface can be used by an application to make sure that the
241** version of SQLite that it is linking against was compiled with
242** the desired setting of the [SQLITE_THREADSAFE] macro.
243**
244** This interface only reports on the compile-time mutex setting
245** of the [SQLITE_THREADSAFE] flag. If SQLite is compiled with
246** SQLITE_THREADSAFE=1 or =2 then mutexes are enabled by default but
247** can be fully or partially disabled using a call to [sqlite3_config()]
248** with the verbs [SQLITE_CONFIG_SINGLETHREAD], [SQLITE_CONFIG_MULTITHREAD],
249** or [SQLITE_CONFIG_SERIALIZED]. ^(The return value of the
250** sqlite3_threadsafe() function shows only the compile-time setting of
251** thread safety, not any run-time changes to that setting made by
252** sqlite3_config(). In other words, the return value from sqlite3_threadsafe()
253** is unchanged by calls to sqlite3_config().)^
254**
255** See the [threading mode] documentation for additional information.
256*/
257SQLITE_API int sqlite3_threadsafe(void);
258
259/*
260** CAPI3REF: Database Connection Handle
261** KEYWORDS: {database connection} {database connections}
262**
263** Each open SQLite database is represented by a pointer to an instance of
264** the opaque structure named "sqlite3". It is useful to think of an sqlite3
265** pointer as an object. The [sqlite3_open()], [sqlite3_open16()], and
266** [sqlite3_open_v2()] interfaces are its constructors, and [sqlite3_close()]
267** and [sqlite3_close_v2()] are its destructors. There are many other
268** interfaces (such as
269** [sqlite3_prepare_v2()], [sqlite3_create_function()], and
270** [sqlite3_busy_timeout()] to name but three) that are methods on an
271** sqlite3 object.
272*/
273typedef struct sqlite3 sqlite3;
274
275/*
276** CAPI3REF: 64-Bit Integer Types
277** KEYWORDS: sqlite_int64 sqlite_uint64
278**
279** Because there is no cross-platform way to specify 64-bit integer types
280** SQLite includes typedefs for 64-bit signed and unsigned integers.
281**
282** The sqlite3_int64 and sqlite3_uint64 are the preferred type definitions.
283** The sqlite_int64 and sqlite_uint64 types are supported for backwards
284** compatibility only.
285**
286** ^The sqlite3_int64 and sqlite_int64 types can store integer values
287** between -9223372036854775808 and +9223372036854775807 inclusive. ^The
288** sqlite3_uint64 and sqlite_uint64 types can store integer values
289** between 0 and +18446744073709551615 inclusive.
290*/
291#ifdef SQLITE_INT64_TYPE
292 typedef SQLITE_INT64_TYPE sqlite_int64;
293# ifdef SQLITE_UINT64_TYPE
294 typedef SQLITE_UINT64_TYPE sqlite_uint64;
295# else
296 typedef unsigned SQLITE_INT64_TYPE sqlite_uint64;
297# endif
298#elif defined(_MSC_VER) || defined(__BORLANDC__)
299 typedef __int64 sqlite_int64;
300 typedef unsigned __int64 sqlite_uint64;
301#else
302 typedef long long int sqlite_int64;
303 typedef unsigned long long int sqlite_uint64;
304#endif
305typedef sqlite_int64 sqlite3_int64;
306typedef sqlite_uint64 sqlite3_uint64;
307
308/*
309** If compiling for a processor that lacks floating point support,
310** substitute integer for floating-point.
311*/
312#ifdef SQLITE_OMIT_FLOATING_POINT
313# define double sqlite3_int64
314#endif
315
316/*
317** CAPI3REF: Closing A Database Connection
318** DESTRUCTOR: sqlite3
319**
320** ^The sqlite3_close() and sqlite3_close_v2() routines are destructors
321** for the [sqlite3] object.
322** ^Calls to sqlite3_close() and sqlite3_close_v2() return [SQLITE_OK] if
323** the [sqlite3] object is successfully destroyed and all associated
324** resources are deallocated.
325**
326** Ideally, applications should [sqlite3_finalize | finalize] all
327** [prepared statements], [sqlite3_blob_close | close] all [BLOB handles], and
328** [sqlite3_backup_finish | finish] all [sqlite3_backup] objects associated
329** with the [sqlite3] object prior to attempting to close the object.
330** ^If the database connection is associated with unfinalized prepared
331** statements, BLOB handlers, and/or unfinished sqlite3_backup objects then
332** sqlite3_close() will leave the database connection open and return
333** [SQLITE_BUSY]. ^If sqlite3_close_v2() is called with unfinalized prepared
334** statements, unclosed BLOB handlers, and/or unfinished sqlite3_backups,
335** it returns [SQLITE_OK] regardless, but instead of deallocating the database
336** connection immediately, it marks the database connection as an unusable
337** "zombie" and makes arrangements to automatically deallocate the database
338** connection after all prepared statements are finalized, all BLOB handles
339** are closed, and all backups have finished. The sqlite3_close_v2() interface
340** is intended for use with host languages that are garbage collected, and
341** where the order in which destructors are called is arbitrary.
342**
343** ^If an [sqlite3] object is destroyed while a transaction is open,
344** the transaction is automatically rolled back.
345**
346** The C parameter to [sqlite3_close(C)] and [sqlite3_close_v2(C)]
347** must be either a NULL
348** pointer or an [sqlite3] object pointer obtained
349** from [sqlite3_open()], [sqlite3_open16()], or
350** [sqlite3_open_v2()], and not previously closed.
351** ^Calling sqlite3_close() or sqlite3_close_v2() with a NULL pointer
352** argument is a harmless no-op.
353*/
354SQLITE_API int sqlite3_close(sqlite3*);
355SQLITE_API int sqlite3_close_v2(sqlite3*);
356
357/*
358** The type for a callback function.
359** This is legacy and deprecated. It is included for historical
360** compatibility and is not documented.
361*/
362typedef int (*sqlite3_callback)(void*,int,char**, char**);
363
364/*
365** CAPI3REF: One-Step Query Execution Interface
366** METHOD: sqlite3
367**
368** The sqlite3_exec() interface is a convenience wrapper around
369** [sqlite3_prepare_v2()], [sqlite3_step()], and [sqlite3_finalize()],
370** that allows an application to run multiple statements of SQL
371** without having to use a lot of C code.
372**
373** ^The sqlite3_exec() interface runs zero or more UTF-8 encoded,
374** semicolon-separate SQL statements passed into its 2nd argument,
375** in the context of the [database connection] passed in as its 1st
376** argument. ^If the callback function of the 3rd argument to
377** sqlite3_exec() is not NULL, then it is invoked for each result row
378** coming out of the evaluated SQL statements. ^The 4th argument to
379** sqlite3_exec() is relayed through to the 1st argument of each
380** callback invocation. ^If the callback pointer to sqlite3_exec()
381** is NULL, then no callback is ever invoked and result rows are
382** ignored.
383**
384** ^If an error occurs while evaluating the SQL statements passed into
385** sqlite3_exec(), then execution of the current statement stops and
386** subsequent statements are skipped. ^If the 5th parameter to sqlite3_exec()
387** is not NULL then any error message is written into memory obtained
388** from [sqlite3_malloc()] and passed back through the 5th parameter.
389** To avoid memory leaks, the application should invoke [sqlite3_free()]
390** on error message strings returned through the 5th parameter of
391** sqlite3_exec() after the error message string is no longer needed.
392** ^If the 5th parameter to sqlite3_exec() is not NULL and no errors
393** occur, then sqlite3_exec() sets the pointer in its 5th parameter to
394** NULL before returning.
395**
396** ^If an sqlite3_exec() callback returns non-zero, the sqlite3_exec()
397** routine returns SQLITE_ABORT without invoking the callback again and
398** without running any subsequent SQL statements.
399**
400** ^The 2nd argument to the sqlite3_exec() callback function is the
401** number of columns in the result. ^The 3rd argument to the sqlite3_exec()
402** callback is an array of pointers to strings obtained as if from
403** [sqlite3_column_text()], one for each column. ^If an element of a
404** result row is NULL then the corresponding string pointer for the
405** sqlite3_exec() callback is a NULL pointer. ^The 4th argument to the
406** sqlite3_exec() callback is an array of pointers to strings where each
407** entry represents the name of corresponding result column as obtained
408** from [sqlite3_column_name()].
409**
410** ^If the 2nd parameter to sqlite3_exec() is a NULL pointer, a pointer
411** to an empty string, or a pointer that contains only whitespace and/or
412** SQL comments, then no SQL statements are evaluated and the database
413** is not changed.
414**
415** Restrictions:
416**
417** <ul>
418** <li> The application must ensure that the 1st parameter to sqlite3_exec()
419** is a valid and open [database connection].
420** <li> The application must not close the [database connection] specified by
421** the 1st parameter to sqlite3_exec() while sqlite3_exec() is running.
422** <li> The application must not modify the SQL statement text passed into
423** the 2nd parameter of sqlite3_exec() while sqlite3_exec() is running.
424** <li> The application must not dereference the arrays or string pointers
425** passed as the 3rd and 4th callback parameters after it returns.
426** </ul>
427*/
428SQLITE_API int sqlite3_exec(
429 sqlite3*, /* An open database */
430 const char *sql, /* SQL to be evaluated */
431 int (*callback)(void*,int,char**,char**), /* Callback function */
432 void *, /* 1st argument to callback */
433 char **errmsg /* Error msg written here */
434);
435
436/*
437** CAPI3REF: Result Codes
438** KEYWORDS: {result code definitions}
439**
440** Many SQLite functions return an integer result code from the set shown
441** here in order to indicate success or failure.
442**
443** New error codes may be added in future versions of SQLite.
444**
445** See also: [extended result code definitions]
446*/
447#define SQLITE_OK 0 /* Successful result */
448/* beginning-of-error-codes */
449#define SQLITE_ERROR 1 /* Generic error */
450#define SQLITE_INTERNAL 2 /* Internal logic error in SQLite */
451#define SQLITE_PERM 3 /* Access permission denied */
452#define SQLITE_ABORT 4 /* Callback routine requested an abort */
453#define SQLITE_BUSY 5 /* The database file is locked */
454#define SQLITE_LOCKED 6 /* A table in the database is locked */
455#define SQLITE_NOMEM 7 /* A malloc() failed */
456#define SQLITE_READONLY 8 /* Attempt to write a readonly database */
457#define SQLITE_INTERRUPT 9 /* Operation terminated by sqlite3_interrupt()*/
458#define SQLITE_IOERR 10 /* Some kind of disk I/O error occurred */
459#define SQLITE_CORRUPT 11 /* The database disk image is malformed */
460#define SQLITE_NOTFOUND 12 /* Unknown opcode in sqlite3_file_control() */
461#define SQLITE_FULL 13 /* Insertion failed because database is full */
462#define SQLITE_CANTOPEN 14 /* Unable to open the database file */
463#define SQLITE_PROTOCOL 15 /* Database lock protocol error */
464#define SQLITE_EMPTY 16 /* Internal use only */
465#define SQLITE_SCHEMA 17 /* The database schema changed */
466#define SQLITE_TOOBIG 18 /* String or BLOB exceeds size limit */
467#define SQLITE_CONSTRAINT 19 /* Abort due to constraint violation */
468#define SQLITE_MISMATCH 20 /* Data type mismatch */
469#define SQLITE_MISUSE 21 /* Library used incorrectly */
470#define SQLITE_NOLFS 22 /* Uses OS features not supported on host */
471#define SQLITE_AUTH 23 /* Authorization denied */
472#define SQLITE_FORMAT 24 /* Not used */
473#define SQLITE_RANGE 25 /* 2nd parameter to sqlite3_bind out of range */
474#define SQLITE_NOTADB 26 /* File opened that is not a database file */
475#define SQLITE_NOTICE 27 /* Notifications from sqlite3_log() */
476#define SQLITE_WARNING 28 /* Warnings from sqlite3_log() */
477#define SQLITE_ROW 100 /* sqlite3_step() has another row ready */
478#define SQLITE_DONE 101 /* sqlite3_step() has finished executing */
479/* end-of-error-codes */
480
481/*
482** CAPI3REF: Extended Result Codes
483** KEYWORDS: {extended result code definitions}
484**
485** In its default configuration, SQLite API routines return one of 30 integer
486** [result codes]. However, experience has shown that many of
487** these result codes are too coarse-grained. They do not provide as
488** much information about problems as programmers might like. In an effort to
489** address this, newer versions of SQLite (version 3.3.8 [dateof:3.3.8]
490** and later) include
491** support for additional result codes that provide more detailed information
492** about errors. These [extended result codes] are enabled or disabled
493** on a per database connection basis using the
494** [sqlite3_extended_result_codes()] API. Or, the extended code for
495** the most recent error can be obtained using
496** [sqlite3_extended_errcode()].
497*/
498#define SQLITE_ERROR_MISSING_COLLSEQ (SQLITE_ERROR | (1<<8))
499#define SQLITE_ERROR_RETRY (SQLITE_ERROR | (2<<8))
500#define SQLITE_ERROR_SNAPSHOT (SQLITE_ERROR | (3<<8))
501#define SQLITE_IOERR_READ (SQLITE_IOERR | (1<<8))
502#define SQLITE_IOERR_SHORT_READ (SQLITE_IOERR | (2<<8))
503#define SQLITE_IOERR_WRITE (SQLITE_IOERR | (3<<8))
504#define SQLITE_IOERR_FSYNC (SQLITE_IOERR | (4<<8))
505#define SQLITE_IOERR_DIR_FSYNC (SQLITE_IOERR | (5<<8))
506#define SQLITE_IOERR_TRUNCATE (SQLITE_IOERR | (6<<8))
507#define SQLITE_IOERR_FSTAT (SQLITE_IOERR | (7<<8))
508#define SQLITE_IOERR_UNLOCK (SQLITE_IOERR | (8<<8))
509#define SQLITE_IOERR_RDLOCK (SQLITE_IOERR | (9<<8))
510#define SQLITE_IOERR_DELETE (SQLITE_IOERR | (10<<8))
511#define SQLITE_IOERR_BLOCKED (SQLITE_IOERR | (11<<8))
512#define SQLITE_IOERR_NOMEM (SQLITE_IOERR | (12<<8))
513#define SQLITE_IOERR_ACCESS (SQLITE_IOERR | (13<<8))
514#define SQLITE_IOERR_CHECKRESERVEDLOCK (SQLITE_IOERR | (14<<8))
515#define SQLITE_IOERR_LOCK (SQLITE_IOERR | (15<<8))
516#define SQLITE_IOERR_CLOSE (SQLITE_IOERR | (16<<8))
517#define SQLITE_IOERR_DIR_CLOSE (SQLITE_IOERR | (17<<8))
518#define SQLITE_IOERR_SHMOPEN (SQLITE_IOERR | (18<<8))
519#define SQLITE_IOERR_SHMSIZE (SQLITE_IOERR | (19<<8))
520#define SQLITE_IOERR_SHMLOCK (SQLITE_IOERR | (20<<8))
521#define SQLITE_IOERR_SHMMAP (SQLITE_IOERR | (21<<8))
522#define SQLITE_IOERR_SEEK (SQLITE_IOERR | (22<<8))
523#define SQLITE_IOERR_DELETE_NOENT (SQLITE_IOERR | (23<<8))
524#define SQLITE_IOERR_MMAP (SQLITE_IOERR | (24<<8))
525#define SQLITE_IOERR_GETTEMPPATH (SQLITE_IOERR | (25<<8))
526#define SQLITE_IOERR_CONVPATH (SQLITE_IOERR | (26<<8))
527#define SQLITE_IOERR_VNODE (SQLITE_IOERR | (27<<8))
528#define SQLITE_IOERR_AUTH (SQLITE_IOERR | (28<<8))
529#define SQLITE_IOERR_BEGIN_ATOMIC (SQLITE_IOERR | (29<<8))
530#define SQLITE_IOERR_COMMIT_ATOMIC (SQLITE_IOERR | (30<<8))
531#define SQLITE_IOERR_ROLLBACK_ATOMIC (SQLITE_IOERR | (31<<8))
532#define SQLITE_IOERR_DATA (SQLITE_IOERR | (32<<8))
533#define SQLITE_IOERR_CORRUPTFS (SQLITE_IOERR | (33<<8))
534#define SQLITE_IOERR_IN_PAGE (SQLITE_IOERR | (34<<8))
535#define SQLITE_LOCKED_SHAREDCACHE (SQLITE_LOCKED | (1<<8))
536#define SQLITE_LOCKED_VTAB (SQLITE_LOCKED | (2<<8))
537#define SQLITE_BUSY_RECOVERY (SQLITE_BUSY | (1<<8))
538#define SQLITE_BUSY_SNAPSHOT (SQLITE_BUSY | (2<<8))
539#define SQLITE_BUSY_TIMEOUT (SQLITE_BUSY | (3<<8))
540#define SQLITE_CANTOPEN_NOTEMPDIR (SQLITE_CANTOPEN | (1<<8))
541#define SQLITE_CANTOPEN_ISDIR (SQLITE_CANTOPEN | (2<<8))
542#define SQLITE_CANTOPEN_FULLPATH (SQLITE_CANTOPEN | (3<<8))
543#define SQLITE_CANTOPEN_CONVPATH (SQLITE_CANTOPEN | (4<<8))
544#define SQLITE_CANTOPEN_DIRTYWAL (SQLITE_CANTOPEN | (5<<8)) /* Not Used */
545#define SQLITE_CANTOPEN_SYMLINK (SQLITE_CANTOPEN | (6<<8))
546#define SQLITE_CORRUPT_VTAB (SQLITE_CORRUPT | (1<<8))
547#define SQLITE_CORRUPT_SEQUENCE (SQLITE_CORRUPT | (2<<8))
548#define SQLITE_CORRUPT_INDEX (SQLITE_CORRUPT | (3<<8))
549#define SQLITE_READONLY_RECOVERY (SQLITE_READONLY | (1<<8))
550#define SQLITE_READONLY_CANTLOCK (SQLITE_READONLY | (2<<8))
551#define SQLITE_READONLY_ROLLBACK (SQLITE_READONLY | (3<<8))
552#define SQLITE_READONLY_DBMOVED (SQLITE_READONLY | (4<<8))
553#define SQLITE_READONLY_CANTINIT (SQLITE_READONLY | (5<<8))
554#define SQLITE_READONLY_DIRECTORY (SQLITE_READONLY | (6<<8))
555#define SQLITE_ABORT_ROLLBACK (SQLITE_ABORT | (2<<8))
556#define SQLITE_CONSTRAINT_CHECK (SQLITE_CONSTRAINT | (1<<8))
557#define SQLITE_CONSTRAINT_COMMITHOOK (SQLITE_CONSTRAINT | (2<<8))
558#define SQLITE_CONSTRAINT_FOREIGNKEY (SQLITE_CONSTRAINT | (3<<8))
559#define SQLITE_CONSTRAINT_FUNCTION (SQLITE_CONSTRAINT | (4<<8))
560#define SQLITE_CONSTRAINT_NOTNULL (SQLITE_CONSTRAINT | (5<<8))
561#define SQLITE_CONSTRAINT_PRIMARYKEY (SQLITE_CONSTRAINT | (6<<8))
562#define SQLITE_CONSTRAINT_TRIGGER (SQLITE_CONSTRAINT | (7<<8))
563#define SQLITE_CONSTRAINT_UNIQUE (SQLITE_CONSTRAINT | (8<<8))
564#define SQLITE_CONSTRAINT_VTAB (SQLITE_CONSTRAINT | (9<<8))
565#define SQLITE_CONSTRAINT_ROWID (SQLITE_CONSTRAINT |(10<<8))
566#define SQLITE_CONSTRAINT_PINNED (SQLITE_CONSTRAINT |(11<<8))
567#define SQLITE_CONSTRAINT_DATATYPE (SQLITE_CONSTRAINT |(12<<8))
568#define SQLITE_NOTICE_RECOVER_WAL (SQLITE_NOTICE | (1<<8))
569#define SQLITE_NOTICE_RECOVER_ROLLBACK (SQLITE_NOTICE | (2<<8))
570#define SQLITE_NOTICE_RBU (SQLITE_NOTICE | (3<<8))
571#define SQLITE_WARNING_AUTOINDEX (SQLITE_WARNING | (1<<8))
572#define SQLITE_AUTH_USER (SQLITE_AUTH | (1<<8))
573#define SQLITE_OK_LOAD_PERMANENTLY (SQLITE_OK | (1<<8))
574#define SQLITE_OK_SYMLINK (SQLITE_OK | (2<<8)) /* internal use only */
575
576/*
577** CAPI3REF: Flags For File Open Operations
578**
579** These bit values are intended for use in the
580** 3rd parameter to the [sqlite3_open_v2()] interface and
581** in the 4th parameter to the [sqlite3_vfs.xOpen] method.
582**
583** Only those flags marked as "Ok for sqlite3_open_v2()" may be
584** used as the third argument to the [sqlite3_open_v2()] interface.
585** The other flags have historically been ignored by sqlite3_open_v2(),
586** though future versions of SQLite might change so that an error is
587** raised if any of the disallowed bits are passed into sqlite3_open_v2().
588** Applications should not depend on the historical behavior.
589**
590** Note in particular that passing the SQLITE_OPEN_EXCLUSIVE flag into
591** [sqlite3_open_v2()] does *not* cause the underlying database file
592** to be opened using O_EXCL. Passing SQLITE_OPEN_EXCLUSIVE into
593** [sqlite3_open_v2()] has historically be a no-op and might become an
594** error in future versions of SQLite.
595*/
596#define SQLITE_OPEN_READONLY 0x00000001 /* Ok for sqlite3_open_v2() */
597#define SQLITE_OPEN_READWRITE 0x00000002 /* Ok for sqlite3_open_v2() */
598#define SQLITE_OPEN_CREATE 0x00000004 /* Ok for sqlite3_open_v2() */
599#define SQLITE_OPEN_DELETEONCLOSE 0x00000008 /* VFS only */
600#define SQLITE_OPEN_EXCLUSIVE 0x00000010 /* VFS only */
601#define SQLITE_OPEN_AUTOPROXY 0x00000020 /* VFS only */
602#define SQLITE_OPEN_URI 0x00000040 /* Ok for sqlite3_open_v2() */
603#define SQLITE_OPEN_MEMORY 0x00000080 /* Ok for sqlite3_open_v2() */
604#define SQLITE_OPEN_MAIN_DB 0x00000100 /* VFS only */
605#define SQLITE_OPEN_TEMP_DB 0x00000200 /* VFS only */
606#define SQLITE_OPEN_TRANSIENT_DB 0x00000400 /* VFS only */
607#define SQLITE_OPEN_MAIN_JOURNAL 0x00000800 /* VFS only */
608#define SQLITE_OPEN_TEMP_JOURNAL 0x00001000 /* VFS only */
609#define SQLITE_OPEN_SUBJOURNAL 0x00002000 /* VFS only */
610#define SQLITE_OPEN_SUPER_JOURNAL 0x00004000 /* VFS only */
611#define SQLITE_OPEN_NOMUTEX 0x00008000 /* Ok for sqlite3_open_v2() */
612#define SQLITE_OPEN_FULLMUTEX 0x00010000 /* Ok for sqlite3_open_v2() */
613#define SQLITE_OPEN_SHAREDCACHE 0x00020000 /* Ok for sqlite3_open_v2() */
614#define SQLITE_OPEN_PRIVATECACHE 0x00040000 /* Ok for sqlite3_open_v2() */
615#define SQLITE_OPEN_WAL 0x00080000 /* VFS only */
616#define SQLITE_OPEN_NOFOLLOW 0x01000000 /* Ok for sqlite3_open_v2() */
617#define SQLITE_OPEN_EXRESCODE 0x02000000 /* Extended result codes */
618
619/* Reserved: 0x00F00000 */
620/* Legacy compatibility: */
621#define SQLITE_OPEN_MASTER_JOURNAL 0x00004000 /* VFS only */
622
623
624/*
625** CAPI3REF: Device Characteristics
626**
627** The xDeviceCharacteristics method of the [sqlite3_io_methods]
628** object returns an integer which is a vector of these
629** bit values expressing I/O characteristics of the mass storage
630** device that holds the file that the [sqlite3_io_methods]
631** refers to.
632**
633** The SQLITE_IOCAP_ATOMIC property means that all writes of
634** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values
635** mean that writes of blocks that are nnn bytes in size and
636** are aligned to an address which is an integer multiple of
637** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means
638** that when data is appended to a file, the data is appended
639** first then the size of the file is extended, never the other
640** way around. The SQLITE_IOCAP_SEQUENTIAL property means that
641** information is written to disk in the same order as calls
642** to xWrite(). The SQLITE_IOCAP_POWERSAFE_OVERWRITE property means that
643** after reboot following a crash or power loss, the only bytes in a
644** file that were written at the application level might have changed
645** and that adjacent bytes, even bytes within the same sector are
646** guaranteed to be unchanged. The SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN
647** flag indicates that a file cannot be deleted when open. The
648** SQLITE_IOCAP_IMMUTABLE flag indicates that the file is on
649** read-only media and cannot be changed even by processes with
650** elevated privileges.
651**
652** The SQLITE_IOCAP_BATCH_ATOMIC property means that the underlying
653** filesystem supports doing multiple write operations atomically when those
654** write operations are bracketed by [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] and
655** [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE].
656**
657** The SQLITE_IOCAP_SUBPAGE_READ property means that it is ok to read
658** from the database file in amounts that are not a multiple of the
659** page size and that do not begin at a page boundary. Without this
660** property, SQLite is careful to only do full-page reads and write
661** on aligned pages, with the one exception that it will do a sub-page
662** read of the first page to access the database header.
663*/
664#define SQLITE_IOCAP_ATOMIC 0x00000001
665#define SQLITE_IOCAP_ATOMIC512 0x00000002
666#define SQLITE_IOCAP_ATOMIC1K 0x00000004
667#define SQLITE_IOCAP_ATOMIC2K 0x00000008
668#define SQLITE_IOCAP_ATOMIC4K 0x00000010
669#define SQLITE_IOCAP_ATOMIC8K 0x00000020
670#define SQLITE_IOCAP_ATOMIC16K 0x00000040
671#define SQLITE_IOCAP_ATOMIC32K 0x00000080
672#define SQLITE_IOCAP_ATOMIC64K 0x00000100
673#define SQLITE_IOCAP_SAFE_APPEND 0x00000200
674#define SQLITE_IOCAP_SEQUENTIAL 0x00000400
675#define SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN 0x00000800
676#define SQLITE_IOCAP_POWERSAFE_OVERWRITE 0x00001000
677#define SQLITE_IOCAP_IMMUTABLE 0x00002000
678#define SQLITE_IOCAP_BATCH_ATOMIC 0x00004000
679#define SQLITE_IOCAP_SUBPAGE_READ 0x00008000
680
681/*
682** CAPI3REF: File Locking Levels
683**
684** SQLite uses one of these integer values as the second
685** argument to calls it makes to the xLock() and xUnlock() methods
686** of an [sqlite3_io_methods] object. These values are ordered from
687** lest restrictive to most restrictive.
688**
689** The argument to xLock() is always SHARED or higher. The argument to
690** xUnlock is either SHARED or NONE.
691*/
692#define SQLITE_LOCK_NONE 0 /* xUnlock() only */
693#define SQLITE_LOCK_SHARED 1 /* xLock() or xUnlock() */
694#define SQLITE_LOCK_RESERVED 2 /* xLock() only */
695#define SQLITE_LOCK_PENDING 3 /* xLock() only */
696#define SQLITE_LOCK_EXCLUSIVE 4 /* xLock() only */
697
698/*
699** CAPI3REF: Synchronization Type Flags
700**
701** When SQLite invokes the xSync() method of an
702** [sqlite3_io_methods] object it uses a combination of
703** these integer values as the second argument.
704**
705** When the SQLITE_SYNC_DATAONLY flag is used, it means that the
706** sync operation only needs to flush data to mass storage. Inode
707** information need not be flushed. If the lower four bits of the flag
708** equal SQLITE_SYNC_NORMAL, that means to use normal fsync() semantics.
709** If the lower four bits equal SQLITE_SYNC_FULL, that means
710** to use Mac OS X style fullsync instead of fsync().
711**
712** Do not confuse the SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags
713** with the [PRAGMA synchronous]=NORMAL and [PRAGMA synchronous]=FULL
714** settings. The [synchronous pragma] determines when calls to the
715** xSync VFS method occur and applies uniformly across all platforms.
716** The SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags determine how
717** energetic or rigorous or forceful the sync operations are and
718** only make a difference on Mac OSX for the default SQLite code.
719** (Third-party VFS implementations might also make the distinction
720** between SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL, but among the
721** operating systems natively supported by SQLite, only Mac OSX
722** cares about the difference.)
723*/
724#define SQLITE_SYNC_NORMAL 0x00002
725#define SQLITE_SYNC_FULL 0x00003
726#define SQLITE_SYNC_DATAONLY 0x00010
727
728/*
729** CAPI3REF: OS Interface Open File Handle
730**
731** An [sqlite3_file] object represents an open file in the
732** [sqlite3_vfs | OS interface layer]. Individual OS interface
733** implementations will
734** want to subclass this object by appending additional fields
735** for their own use. The pMethods entry is a pointer to an
736** [sqlite3_io_methods] object that defines methods for performing
737** I/O operations on the open file.
738*/
739typedef struct sqlite3_file sqlite3_file;
740struct sqlite3_file {
741 const struct sqlite3_io_methods *pMethods; /* Methods for an open file */
742};
743
744/*
745** CAPI3REF: OS Interface File Virtual Methods Object
746**
747** Every file opened by the [sqlite3_vfs.xOpen] method populates an
748** [sqlite3_file] object (or, more commonly, a subclass of the
749** [sqlite3_file] object) with a pointer to an instance of this object.
750** This object defines the methods used to perform various operations
751** against the open file represented by the [sqlite3_file] object.
752**
753** If the [sqlite3_vfs.xOpen] method sets the sqlite3_file.pMethods element
754** to a non-NULL pointer, then the sqlite3_io_methods.xClose method
755** may be invoked even if the [sqlite3_vfs.xOpen] reported that it failed. The
756** only way to prevent a call to xClose following a failed [sqlite3_vfs.xOpen]
757** is for the [sqlite3_vfs.xOpen] to set the sqlite3_file.pMethods element
758** to NULL.
759**
760** The flags argument to xSync may be one of [SQLITE_SYNC_NORMAL] or
761** [SQLITE_SYNC_FULL]. The first choice is the normal fsync().
762** The second choice is a Mac OS X style fullsync. The [SQLITE_SYNC_DATAONLY]
763** flag may be ORed in to indicate that only the data of the file
764** and not its inode needs to be synced.
765**
766** The integer values to xLock() and xUnlock() are one of
767** <ul>
768** <li> [SQLITE_LOCK_NONE],
769** <li> [SQLITE_LOCK_SHARED],
770** <li> [SQLITE_LOCK_RESERVED],
771** <li> [SQLITE_LOCK_PENDING], or
772** <li> [SQLITE_LOCK_EXCLUSIVE].
773** </ul>
774** xLock() upgrades the database file lock. In other words, xLock() moves the
775** database file lock in the direction NONE toward EXCLUSIVE. The argument to
776** xLock() is always one of SHARED, RESERVED, PENDING, or EXCLUSIVE, never
777** SQLITE_LOCK_NONE. If the database file lock is already at or above the
778** requested lock, then the call to xLock() is a no-op.
779** xUnlock() downgrades the database file lock to either SHARED or NONE.
780** If the lock is already at or below the requested lock state, then the call
781** to xUnlock() is a no-op.
782** The xCheckReservedLock() method checks whether any database connection,
783** either in this process or in some other process, is holding a RESERVED,
784** PENDING, or EXCLUSIVE lock on the file. It returns, via its output
785** pointer parameter, true if such a lock exists and false otherwise.
786**
787** The xFileControl() method is a generic interface that allows custom
788** VFS implementations to directly control an open file using the
789** [sqlite3_file_control()] interface. The second "op" argument is an
790** integer opcode. The third argument is a generic pointer intended to
791** point to a structure that may contain arguments or space in which to
792** write return values. Potential uses for xFileControl() might be
793** functions to enable blocking locks with timeouts, to change the
794** locking strategy (for example to use dot-file locks), to inquire
795** about the status of a lock, or to break stale locks. The SQLite
796** core reserves all opcodes less than 100 for its own use.
797** A [file control opcodes | list of opcodes] less than 100 is available.
798** Applications that define a custom xFileControl method should use opcodes
799** greater than 100 to avoid conflicts. VFS implementations should
800** return [SQLITE_NOTFOUND] for file control opcodes that they do not
801** recognize.
802**
803** The xSectorSize() method returns the sector size of the
804** device that underlies the file. The sector size is the
805** minimum write that can be performed without disturbing
806** other bytes in the file. The xDeviceCharacteristics()
807** method returns a bit vector describing behaviors of the
808** underlying device:
809**
810** <ul>
811** <li> [SQLITE_IOCAP_ATOMIC]
812** <li> [SQLITE_IOCAP_ATOMIC512]
813** <li> [SQLITE_IOCAP_ATOMIC1K]
814** <li> [SQLITE_IOCAP_ATOMIC2K]
815** <li> [SQLITE_IOCAP_ATOMIC4K]
816** <li> [SQLITE_IOCAP_ATOMIC8K]
817** <li> [SQLITE_IOCAP_ATOMIC16K]
818** <li> [SQLITE_IOCAP_ATOMIC32K]
819** <li> [SQLITE_IOCAP_ATOMIC64K]
820** <li> [SQLITE_IOCAP_SAFE_APPEND]
821** <li> [SQLITE_IOCAP_SEQUENTIAL]
822** <li> [SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN]
823** <li> [SQLITE_IOCAP_POWERSAFE_OVERWRITE]
824** <li> [SQLITE_IOCAP_IMMUTABLE]
825** <li> [SQLITE_IOCAP_BATCH_ATOMIC]
826** <li> [SQLITE_IOCAP_SUBPAGE_READ]
827** </ul>
828**
829** The SQLITE_IOCAP_ATOMIC property means that all writes of
830** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values
831** mean that writes of blocks that are nnn bytes in size and
832** are aligned to an address which is an integer multiple of
833** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means
834** that when data is appended to a file, the data is appended
835** first then the size of the file is extended, never the other
836** way around. The SQLITE_IOCAP_SEQUENTIAL property means that
837** information is written to disk in the same order as calls
838** to xWrite().
839**
840** If xRead() returns SQLITE_IOERR_SHORT_READ it must also fill
841** in the unread portions of the buffer with zeros. A VFS that
842** fails to zero-fill short reads might seem to work. However,
843** failure to zero-fill short reads will eventually lead to
844** database corruption.
845*/
846typedef struct sqlite3_io_methods sqlite3_io_methods;
847struct sqlite3_io_methods {
848 int iVersion;
849 int (*xClose)(sqlite3_file*);
850 int (*xRead)(sqlite3_file*, void*, int iAmt, sqlite3_int64 iOfst);
851 int (*xWrite)(sqlite3_file*, const void*, int iAmt, sqlite3_int64 iOfst);
852 int (*xTruncate)(sqlite3_file*, sqlite3_int64 size);
853 int (*xSync)(sqlite3_file*, int flags);
854 int (*xFileSize)(sqlite3_file*, sqlite3_int64 *pSize);
855 int (*xLock)(sqlite3_file*, int);
856 int (*xUnlock)(sqlite3_file*, int);
857 int (*xCheckReservedLock)(sqlite3_file*, int *pResOut);
858 int (*xFileControl)(sqlite3_file*, int op, void *pArg);
859 int (*xSectorSize)(sqlite3_file*);
860 int (*xDeviceCharacteristics)(sqlite3_file*);
861 /* Methods above are valid for version 1 */
862 int (*xShmMap)(sqlite3_file*, int iPg, int pgsz, int, void volatile**);
863 int (*xShmLock)(sqlite3_file*, int offset, int n, int flags);
864 void (*xShmBarrier)(sqlite3_file*);
865 int (*xShmUnmap)(sqlite3_file*, int deleteFlag);
866 /* Methods above are valid for version 2 */
867 int (*xFetch)(sqlite3_file*, sqlite3_int64 iOfst, int iAmt, void **pp);
868 int (*xUnfetch)(sqlite3_file*, sqlite3_int64 iOfst, void *p);
869 /* Methods above are valid for version 3 */
870 /* Additional methods may be added in future releases */
871};
872
873/*
874** CAPI3REF: Standard File Control Opcodes
875** KEYWORDS: {file control opcodes} {file control opcode}
876**
877** These integer constants are opcodes for the xFileControl method
878** of the [sqlite3_io_methods] object and for the [sqlite3_file_control()]
879** interface.
880**
881** <ul>
882** <li>[[SQLITE_FCNTL_LOCKSTATE]]
883** The [SQLITE_FCNTL_LOCKSTATE] opcode is used for debugging. This
884** opcode causes the xFileControl method to write the current state of
885** the lock (one of [SQLITE_LOCK_NONE], [SQLITE_LOCK_SHARED],
886** [SQLITE_LOCK_RESERVED], [SQLITE_LOCK_PENDING], or [SQLITE_LOCK_EXCLUSIVE])
887** into an integer that the pArg argument points to.
888** This capability is only available if SQLite is compiled with [SQLITE_DEBUG].
889**
890** <li>[[SQLITE_FCNTL_SIZE_HINT]]
891** The [SQLITE_FCNTL_SIZE_HINT] opcode is used by SQLite to give the VFS
892** layer a hint of how large the database file will grow to be during the
893** current transaction. This hint is not guaranteed to be accurate but it
894** is often close. The underlying VFS might choose to preallocate database
895** file space based on this hint in order to help writes to the database
896** file run faster.
897**
898** <li>[[SQLITE_FCNTL_SIZE_LIMIT]]
899** The [SQLITE_FCNTL_SIZE_LIMIT] opcode is used by in-memory VFS that
900** implements [sqlite3_deserialize()] to set an upper bound on the size
901** of the in-memory database. The argument is a pointer to a [sqlite3_int64].
902** If the integer pointed to is negative, then it is filled in with the
903** current limit. Otherwise the limit is set to the larger of the value
904** of the integer pointed to and the current database size. The integer
905** pointed to is set to the new limit.
906**
907** <li>[[SQLITE_FCNTL_CHUNK_SIZE]]
908** The [SQLITE_FCNTL_CHUNK_SIZE] opcode is used to request that the VFS
909** extends and truncates the database file in chunks of a size specified
910** by the user. The fourth argument to [sqlite3_file_control()] should
911** point to an integer (type int) containing the new chunk-size to use
912** for the nominated database. Allocating database file space in large
913** chunks (say 1MB at a time), may reduce file-system fragmentation and
914** improve performance on some systems.
915**
916** <li>[[SQLITE_FCNTL_FILE_POINTER]]
917** The [SQLITE_FCNTL_FILE_POINTER] opcode is used to obtain a pointer
918** to the [sqlite3_file] object associated with a particular database
919** connection. See also [SQLITE_FCNTL_JOURNAL_POINTER].
920**
921** <li>[[SQLITE_FCNTL_JOURNAL_POINTER]]
922** The [SQLITE_FCNTL_JOURNAL_POINTER] opcode is used to obtain a pointer
923** to the [sqlite3_file] object associated with the journal file (either
924** the [rollback journal] or the [write-ahead log]) for a particular database
925** connection. See also [SQLITE_FCNTL_FILE_POINTER].
926**
927** <li>[[SQLITE_FCNTL_SYNC_OMITTED]]
928** No longer in use.
929**
930** <li>[[SQLITE_FCNTL_SYNC]]
931** The [SQLITE_FCNTL_SYNC] opcode is generated internally by SQLite and
932** sent to the VFS immediately before the xSync method is invoked on a
933** database file descriptor. Or, if the xSync method is not invoked
934** because the user has configured SQLite with
935** [PRAGMA synchronous | PRAGMA synchronous=OFF] it is invoked in place
936** of the xSync method. In most cases, the pointer argument passed with
937** this file-control is NULL. However, if the database file is being synced
938** as part of a multi-database commit, the argument points to a nul-terminated
939** string containing the transactions super-journal file name. VFSes that
940** do not need this signal should silently ignore this opcode. Applications
941** should not call [sqlite3_file_control()] with this opcode as doing so may
942** disrupt the operation of the specialized VFSes that do require it.
943**
944** <li>[[SQLITE_FCNTL_COMMIT_PHASETWO]]
945** The [SQLITE_FCNTL_COMMIT_PHASETWO] opcode is generated internally by SQLite
946** and sent to the VFS after a transaction has been committed immediately
947** but before the database is unlocked. VFSes that do not need this signal
948** should silently ignore this opcode. Applications should not call
949** [sqlite3_file_control()] with this opcode as doing so may disrupt the
950** operation of the specialized VFSes that do require it.
951**
952** <li>[[SQLITE_FCNTL_WIN32_AV_RETRY]]
953** ^The [SQLITE_FCNTL_WIN32_AV_RETRY] opcode is used to configure automatic
954** retry counts and intervals for certain disk I/O operations for the
955** windows [VFS] in order to provide robustness in the presence of
956** anti-virus programs. By default, the windows VFS will retry file read,
957** file write, and file delete operations up to 10 times, with a delay
958** of 25 milliseconds before the first retry and with the delay increasing
959** by an additional 25 milliseconds with each subsequent retry. This
960** opcode allows these two values (10 retries and 25 milliseconds of delay)
961** to be adjusted. The values are changed for all database connections
962** within the same process. The argument is a pointer to an array of two
963** integers where the first integer is the new retry count and the second
964** integer is the delay. If either integer is negative, then the setting
965** is not changed but instead the prior value of that setting is written
966** into the array entry, allowing the current retry settings to be
967** interrogated. The zDbName parameter is ignored.
968**
969** <li>[[SQLITE_FCNTL_PERSIST_WAL]]
970** ^The [SQLITE_FCNTL_PERSIST_WAL] opcode is used to set or query the
971** persistent [WAL | Write Ahead Log] setting. By default, the auxiliary
972** write ahead log ([WAL file]) and shared memory
973** files used for transaction control
974** are automatically deleted when the latest connection to the database
975** closes. Setting persistent WAL mode causes those files to persist after
976** close. Persisting the files is useful when other processes that do not
977** have write permission on the directory containing the database file want
978** to read the database file, as the WAL and shared memory files must exist
979** in order for the database to be readable. The fourth parameter to
980** [sqlite3_file_control()] for this opcode should be a pointer to an integer.
981** That integer is 0 to disable persistent WAL mode or 1 to enable persistent
982** WAL mode. If the integer is -1, then it is overwritten with the current
983** WAL persistence setting.
984**
985** <li>[[SQLITE_FCNTL_POWERSAFE_OVERWRITE]]
986** ^The [SQLITE_FCNTL_POWERSAFE_OVERWRITE] opcode is used to set or query the
987** persistent "powersafe-overwrite" or "PSOW" setting. The PSOW setting
988** determines the [SQLITE_IOCAP_POWERSAFE_OVERWRITE] bit of the
989** xDeviceCharacteristics methods. The fourth parameter to
990** [sqlite3_file_control()] for this opcode should be a pointer to an integer.
991** That integer is 0 to disable zero-damage mode or 1 to enable zero-damage
992** mode. If the integer is -1, then it is overwritten with the current
993** zero-damage mode setting.
994**
995** <li>[[SQLITE_FCNTL_OVERWRITE]]
996** ^The [SQLITE_FCNTL_OVERWRITE] opcode is invoked by SQLite after opening
997** a write transaction to indicate that, unless it is rolled back for some
998** reason, the entire database file will be overwritten by the current
999** transaction. This is used by VACUUM operations.
1000**
1001** <li>[[SQLITE_FCNTL_VFSNAME]]
1002** ^The [SQLITE_FCNTL_VFSNAME] opcode can be used to obtain the names of
1003** all [VFSes] in the VFS stack. The names are of all VFS shims and the
1004** final bottom-level VFS are written into memory obtained from
1005** [sqlite3_malloc()] and the result is stored in the char* variable
1006** that the fourth parameter of [sqlite3_file_control()] points to.
1007** The caller is responsible for freeing the memory when done. As with
1008** all file-control actions, there is no guarantee that this will actually
1009** do anything. Callers should initialize the char* variable to a NULL
1010** pointer in case this file-control is not implemented. This file-control
1011** is intended for diagnostic use only.
1012**
1013** <li>[[SQLITE_FCNTL_VFS_POINTER]]
1014** ^The [SQLITE_FCNTL_VFS_POINTER] opcode finds a pointer to the top-level
1015** [VFSes] currently in use. ^(The argument X in
1016** sqlite3_file_control(db,SQLITE_FCNTL_VFS_POINTER,X) must be
1017** of type "[sqlite3_vfs] **". This opcodes will set *X
1018** to a pointer to the top-level VFS.)^
1019** ^When there are multiple VFS shims in the stack, this opcode finds the
1020** upper-most shim only.
1021**
1022** <li>[[SQLITE_FCNTL_PRAGMA]]
1023** ^Whenever a [PRAGMA] statement is parsed, an [SQLITE_FCNTL_PRAGMA]
1024** file control is sent to the open [sqlite3_file] object corresponding
1025** to the database file to which the pragma statement refers. ^The argument
1026** to the [SQLITE_FCNTL_PRAGMA] file control is an array of
1027** pointers to strings (char**) in which the second element of the array
1028** is the name of the pragma and the third element is the argument to the
1029** pragma or NULL if the pragma has no argument. ^The handler for an
1030** [SQLITE_FCNTL_PRAGMA] file control can optionally make the first element
1031** of the char** argument point to a string obtained from [sqlite3_mprintf()]
1032** or the equivalent and that string will become the result of the pragma or
1033** the error message if the pragma fails. ^If the
1034** [SQLITE_FCNTL_PRAGMA] file control returns [SQLITE_NOTFOUND], then normal
1035** [PRAGMA] processing continues. ^If the [SQLITE_FCNTL_PRAGMA]
1036** file control returns [SQLITE_OK], then the parser assumes that the
1037** VFS has handled the PRAGMA itself and the parser generates a no-op
1038** prepared statement if result string is NULL, or that returns a copy
1039** of the result string if the string is non-NULL.
1040** ^If the [SQLITE_FCNTL_PRAGMA] file control returns
1041** any result code other than [SQLITE_OK] or [SQLITE_NOTFOUND], that means
1042** that the VFS encountered an error while handling the [PRAGMA] and the
1043** compilation of the PRAGMA fails with an error. ^The [SQLITE_FCNTL_PRAGMA]
1044** file control occurs at the beginning of pragma statement analysis and so
1045** it is able to override built-in [PRAGMA] statements.
1046**
1047** <li>[[SQLITE_FCNTL_BUSYHANDLER]]
1048** ^The [SQLITE_FCNTL_BUSYHANDLER]
1049** file-control may be invoked by SQLite on the database file handle
1050** shortly after it is opened in order to provide a custom VFS with access
1051** to the connection's busy-handler callback. The argument is of type (void**)
1052** - an array of two (void *) values. The first (void *) actually points
1053** to a function of type (int (*)(void *)). In order to invoke the connection's
1054** busy-handler, this function should be invoked with the second (void *) in
1055** the array as the only argument. If it returns non-zero, then the operation
1056** should be retried. If it returns zero, the custom VFS should abandon the
1057** current operation.
1058**
1059** <li>[[SQLITE_FCNTL_TEMPFILENAME]]
1060** ^Applications can invoke the [SQLITE_FCNTL_TEMPFILENAME] file-control
1061** to have SQLite generate a
1062** temporary filename using the same algorithm that is followed to generate
1063** temporary filenames for TEMP tables and other internal uses. The
1064** argument should be a char** which will be filled with the filename
1065** written into memory obtained from [sqlite3_malloc()]. The caller should
1066** invoke [sqlite3_free()] on the result to avoid a memory leak.
1067**
1068** <li>[[SQLITE_FCNTL_MMAP_SIZE]]
1069** The [SQLITE_FCNTL_MMAP_SIZE] file control is used to query or set the
1070** maximum number of bytes that will be used for memory-mapped I/O.
1071** The argument is a pointer to a value of type sqlite3_int64 that
1072** is an advisory maximum number of bytes in the file to memory map. The
1073** pointer is overwritten with the old value. The limit is not changed if
1074** the value originally pointed to is negative, and so the current limit
1075** can be queried by passing in a pointer to a negative number. This
1076** file-control is used internally to implement [PRAGMA mmap_size].
1077**
1078** <li>[[SQLITE_FCNTL_TRACE]]
1079** The [SQLITE_FCNTL_TRACE] file control provides advisory information
1080** to the VFS about what the higher layers of the SQLite stack are doing.
1081** This file control is used by some VFS activity tracing [shims].
1082** The argument is a zero-terminated string. Higher layers in the
1083** SQLite stack may generate instances of this file control if
1084** the [SQLITE_USE_FCNTL_TRACE] compile-time option is enabled.
1085**
1086** <li>[[SQLITE_FCNTL_HAS_MOVED]]
1087** The [SQLITE_FCNTL_HAS_MOVED] file control interprets its argument as a
1088** pointer to an integer and it writes a boolean into that integer depending
1089** on whether or not the file has been renamed, moved, or deleted since it
1090** was first opened.
1091**
1092** <li>[[SQLITE_FCNTL_WIN32_GET_HANDLE]]
1093** The [SQLITE_FCNTL_WIN32_GET_HANDLE] opcode can be used to obtain the
1094** underlying native file handle associated with a file handle. This file
1095** control interprets its argument as a pointer to a native file handle and
1096** writes the resulting value there.
1097**
1098** <li>[[SQLITE_FCNTL_WIN32_SET_HANDLE]]
1099** The [SQLITE_FCNTL_WIN32_SET_HANDLE] opcode is used for debugging. This
1100** opcode causes the xFileControl method to swap the file handle with the one
1101** pointed to by the pArg argument. This capability is used during testing
1102** and only needs to be supported when SQLITE_TEST is defined.
1103**
1104** <li>[[SQLITE_FCNTL_NULL_IO]]
1105** The [SQLITE_FCNTL_NULL_IO] opcode sets the low-level file descriptor
1106** or file handle for the [sqlite3_file] object such that it will no longer
1107** read or write to the database file.
1108**
1109** <li>[[SQLITE_FCNTL_WAL_BLOCK]]
1110** The [SQLITE_FCNTL_WAL_BLOCK] is a signal to the VFS layer that it might
1111** be advantageous to block on the next WAL lock if the lock is not immediately
1112** available. The WAL subsystem issues this signal during rare
1113** circumstances in order to fix a problem with priority inversion.
1114** Applications should <em>not</em> use this file-control.
1115**
1116** <li>[[SQLITE_FCNTL_ZIPVFS]]
1117** The [SQLITE_FCNTL_ZIPVFS] opcode is implemented by zipvfs only. All other
1118** VFS should return SQLITE_NOTFOUND for this opcode.
1119**
1120** <li>[[SQLITE_FCNTL_RBU]]
1121** The [SQLITE_FCNTL_RBU] opcode is implemented by the special VFS used by
1122** the RBU extension only. All other VFS should return SQLITE_NOTFOUND for
1123** this opcode.
1124**
1125** <li>[[SQLITE_FCNTL_BEGIN_ATOMIC_WRITE]]
1126** If the [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] opcode returns SQLITE_OK, then
1127** the file descriptor is placed in "batch write mode", which
1128** means all subsequent write operations will be deferred and done
1129** atomically at the next [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE]. Systems
1130** that do not support batch atomic writes will return SQLITE_NOTFOUND.
1131** ^Following a successful SQLITE_FCNTL_BEGIN_ATOMIC_WRITE and prior to
1132** the closing [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE] or
1133** [SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE], SQLite will make
1134** no VFS interface calls on the same [sqlite3_file] file descriptor
1135** except for calls to the xWrite method and the xFileControl method
1136** with [SQLITE_FCNTL_SIZE_HINT].
1137**
1138** <li>[[SQLITE_FCNTL_COMMIT_ATOMIC_WRITE]]
1139** The [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE] opcode causes all write
1140** operations since the previous successful call to
1141** [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] to be performed atomically.
1142** This file control returns [SQLITE_OK] if and only if the writes were
1143** all performed successfully and have been committed to persistent storage.
1144** ^Regardless of whether or not it is successful, this file control takes
1145** the file descriptor out of batch write mode so that all subsequent
1146** write operations are independent.
1147** ^SQLite will never invoke SQLITE_FCNTL_COMMIT_ATOMIC_WRITE without
1148** a prior successful call to [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE].
1149**
1150** <li>[[SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE]]
1151** The [SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE] opcode causes all write
1152** operations since the previous successful call to
1153** [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] to be rolled back.
1154** ^This file control takes the file descriptor out of batch write mode
1155** so that all subsequent write operations are independent.
1156** ^SQLite will never invoke SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE without
1157** a prior successful call to [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE].
1158**
1159** <li>[[SQLITE_FCNTL_LOCK_TIMEOUT]]
1160** The [SQLITE_FCNTL_LOCK_TIMEOUT] opcode is used to configure a VFS
1161** to block for up to M milliseconds before failing when attempting to
1162** obtain a file lock using the xLock or xShmLock methods of the VFS.
1163** The parameter is a pointer to a 32-bit signed integer that contains
1164** the value that M is to be set to. Before returning, the 32-bit signed
1165** integer is overwritten with the previous value of M.
1166**
1167** <li>[[SQLITE_FCNTL_BLOCK_ON_CONNECT]]
1168** The [SQLITE_FCNTL_BLOCK_ON_CONNECT] opcode is used to configure the
1169** VFS to block when taking a SHARED lock to connect to a wal mode database.
1170** This is used to implement the functionality associated with
1171** SQLITE_SETLK_BLOCK_ON_CONNECT.
1172**
1173** <li>[[SQLITE_FCNTL_DATA_VERSION]]
1174** The [SQLITE_FCNTL_DATA_VERSION] opcode is used to detect changes to
1175** a database file. The argument is a pointer to a 32-bit unsigned integer.
1176** The "data version" for the pager is written into the pointer. The
1177** "data version" changes whenever any change occurs to the corresponding
1178** database file, either through SQL statements on the same database
1179** connection or through transactions committed by separate database
1180** connections possibly in other processes. The [sqlite3_total_changes()]
1181** interface can be used to find if any database on the connection has changed,
1182** but that interface responds to changes on TEMP as well as MAIN and does
1183** not provide a mechanism to detect changes to MAIN only. Also, the
1184** [sqlite3_total_changes()] interface responds to internal changes only and
1185** omits changes made by other database connections. The
1186** [PRAGMA data_version] command provides a mechanism to detect changes to
1187** a single attached database that occur due to other database connections,
1188** but omits changes implemented by the database connection on which it is
1189** called. This file control is the only mechanism to detect changes that
1190** happen either internally or externally and that are associated with
1191** a particular attached database.
1192**
1193** <li>[[SQLITE_FCNTL_CKPT_START]]
1194** The [SQLITE_FCNTL_CKPT_START] opcode is invoked from within a checkpoint
1195** in wal mode before the client starts to copy pages from the wal
1196** file to the database file.
1197**
1198** <li>[[SQLITE_FCNTL_CKPT_DONE]]
1199** The [SQLITE_FCNTL_CKPT_DONE] opcode is invoked from within a checkpoint
1200** in wal mode after the client has finished copying pages from the wal
1201** file to the database file, but before the *-shm file is updated to
1202** record the fact that the pages have been checkpointed.
1203**
1204** <li>[[SQLITE_FCNTL_EXTERNAL_READER]]
1205** The EXPERIMENTAL [SQLITE_FCNTL_EXTERNAL_READER] opcode is used to detect
1206** whether or not there is a database client in another process with a wal-mode
1207** transaction open on the database or not. It is only available on unix.The
1208** (void*) argument passed with this file-control should be a pointer to a
1209** value of type (int). The integer value is set to 1 if the database is a wal
1210** mode database and there exists at least one client in another process that
1211** currently has an SQL transaction open on the database. It is set to 0 if
1212** the database is not a wal-mode db, or if there is no such connection in any
1213** other process. This opcode cannot be used to detect transactions opened
1214** by clients within the current process, only within other processes.
1215**
1216** <li>[[SQLITE_FCNTL_CKSM_FILE]]
1217** The [SQLITE_FCNTL_CKSM_FILE] opcode is for use internally by the
1218** [checksum VFS shim] only.
1219**
1220** <li>[[SQLITE_FCNTL_RESET_CACHE]]
1221** If there is currently no transaction open on the database, and the
1222** database is not a temp db, then the [SQLITE_FCNTL_RESET_CACHE] file-control
1223** purges the contents of the in-memory page cache. If there is an open
1224** transaction, or if the db is a temp-db, this opcode is a no-op, not an error.
1225** </ul>
1226*/
1227#define SQLITE_FCNTL_LOCKSTATE 1
1228#define SQLITE_FCNTL_GET_LOCKPROXYFILE 2
1229#define SQLITE_FCNTL_SET_LOCKPROXYFILE 3
1230#define SQLITE_FCNTL_LAST_ERRNO 4
1231#define SQLITE_FCNTL_SIZE_HINT 5
1232#define SQLITE_FCNTL_CHUNK_SIZE 6
1233#define SQLITE_FCNTL_FILE_POINTER 7
1234#define SQLITE_FCNTL_SYNC_OMITTED 8
1235#define SQLITE_FCNTL_WIN32_AV_RETRY 9
1236#define SQLITE_FCNTL_PERSIST_WAL 10
1237#define SQLITE_FCNTL_OVERWRITE 11
1238#define SQLITE_FCNTL_VFSNAME 12
1239#define SQLITE_FCNTL_POWERSAFE_OVERWRITE 13
1240#define SQLITE_FCNTL_PRAGMA 14
1241#define SQLITE_FCNTL_BUSYHANDLER 15
1242#define SQLITE_FCNTL_TEMPFILENAME 16
1243#define SQLITE_FCNTL_MMAP_SIZE 18
1244#define SQLITE_FCNTL_TRACE 19
1245#define SQLITE_FCNTL_HAS_MOVED 20
1246#define SQLITE_FCNTL_SYNC 21
1247#define SQLITE_FCNTL_COMMIT_PHASETWO 22
1248#define SQLITE_FCNTL_WIN32_SET_HANDLE 23
1249#define SQLITE_FCNTL_WAL_BLOCK 24
1250#define SQLITE_FCNTL_ZIPVFS 25
1251#define SQLITE_FCNTL_RBU 26
1252#define SQLITE_FCNTL_VFS_POINTER 27
1253#define SQLITE_FCNTL_JOURNAL_POINTER 28
1254#define SQLITE_FCNTL_WIN32_GET_HANDLE 29
1255#define SQLITE_FCNTL_PDB 30
1256#define SQLITE_FCNTL_BEGIN_ATOMIC_WRITE 31
1257#define SQLITE_FCNTL_COMMIT_ATOMIC_WRITE 32
1258#define SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE 33
1259#define SQLITE_FCNTL_LOCK_TIMEOUT 34
1260#define SQLITE_FCNTL_DATA_VERSION 35
1261#define SQLITE_FCNTL_SIZE_LIMIT 36
1262#define SQLITE_FCNTL_CKPT_DONE 37
1263#define SQLITE_FCNTL_RESERVE_BYTES 38
1264#define SQLITE_FCNTL_CKPT_START 39
1265#define SQLITE_FCNTL_EXTERNAL_READER 40
1266#define SQLITE_FCNTL_CKSM_FILE 41
1267#define SQLITE_FCNTL_RESET_CACHE 42
1268#define SQLITE_FCNTL_NULL_IO 43
1269#define SQLITE_FCNTL_BLOCK_ON_CONNECT 44
1270
1271/* deprecated names */
1272#define SQLITE_GET_LOCKPROXYFILE SQLITE_FCNTL_GET_LOCKPROXYFILE
1273#define SQLITE_SET_LOCKPROXYFILE SQLITE_FCNTL_SET_LOCKPROXYFILE
1274#define SQLITE_LAST_ERRNO SQLITE_FCNTL_LAST_ERRNO
1275
1276
1277/*
1278** CAPI3REF: Mutex Handle
1279**
1280** The mutex module within SQLite defines [sqlite3_mutex] to be an
1281** abstract type for a mutex object. The SQLite core never looks
1282** at the internal representation of an [sqlite3_mutex]. It only
1283** deals with pointers to the [sqlite3_mutex] object.
1284**
1285** Mutexes are created using [sqlite3_mutex_alloc()].
1286*/
1287typedef struct sqlite3_mutex sqlite3_mutex;
1288
1289/*
1290** CAPI3REF: Loadable Extension Thunk
1291**
1292** A pointer to the opaque sqlite3_api_routines structure is passed as
1293** the third parameter to entry points of [loadable extensions]. This
1294** structure must be typedefed in order to work around compiler warnings
1295** on some platforms.
1296*/
1297typedef struct sqlite3_api_routines sqlite3_api_routines;
1298
1299/*
1300** CAPI3REF: File Name
1301**
1302** Type [sqlite3_filename] is used by SQLite to pass filenames to the
1303** xOpen method of a [VFS]. It may be cast to (const char*) and treated
1304** as a normal, nul-terminated, UTF-8 buffer containing the filename, but
1305** may also be passed to special APIs such as:
1306**
1307** <ul>
1308** <li> sqlite3_filename_database()
1309** <li> sqlite3_filename_journal()
1310** <li> sqlite3_filename_wal()
1311** <li> sqlite3_uri_parameter()
1312** <li> sqlite3_uri_boolean()
1313** <li> sqlite3_uri_int64()
1314** <li> sqlite3_uri_key()
1315** </ul>
1316*/
1317typedef const char *sqlite3_filename;
1318
1319/*
1320** CAPI3REF: OS Interface Object
1321**
1322** An instance of the sqlite3_vfs object defines the interface between
1323** the SQLite core and the underlying operating system. The "vfs"
1324** in the name of the object stands for "virtual file system". See
1325** the [VFS | VFS documentation] for further information.
1326**
1327** The VFS interface is sometimes extended by adding new methods onto
1328** the end. Each time such an extension occurs, the iVersion field
1329** is incremented. The iVersion value started out as 1 in
1330** SQLite [version 3.5.0] on [dateof:3.5.0], then increased to 2
1331** with SQLite [version 3.7.0] on [dateof:3.7.0], and then increased
1332** to 3 with SQLite [version 3.7.6] on [dateof:3.7.6]. Additional fields
1333** may be appended to the sqlite3_vfs object and the iVersion value
1334** may increase again in future versions of SQLite.
1335** Note that due to an oversight, the structure
1336** of the sqlite3_vfs object changed in the transition from
1337** SQLite [version 3.5.9] to [version 3.6.0] on [dateof:3.6.0]
1338** and yet the iVersion field was not increased.
1339**
1340** The szOsFile field is the size of the subclassed [sqlite3_file]
1341** structure used by this VFS. mxPathname is the maximum length of
1342** a pathname in this VFS.
1343**
1344** Registered sqlite3_vfs objects are kept on a linked list formed by
1345** the pNext pointer. The [sqlite3_vfs_register()]
1346** and [sqlite3_vfs_unregister()] interfaces manage this list
1347** in a thread-safe way. The [sqlite3_vfs_find()] interface
1348** searches the list. Neither the application code nor the VFS
1349** implementation should use the pNext pointer.
1350**
1351** The pNext field is the only field in the sqlite3_vfs
1352** structure that SQLite will ever modify. SQLite will only access
1353** or modify this field while holding a particular static mutex.
1354** The application should never modify anything within the sqlite3_vfs
1355** object once the object has been registered.
1356**
1357** The zName field holds the name of the VFS module. The name must
1358** be unique across all VFS modules.
1359**
1360** [[sqlite3_vfs.xOpen]]
1361** ^SQLite guarantees that the zFilename parameter to xOpen
1362** is either a NULL pointer or string obtained
1363** from xFullPathname() with an optional suffix added.
1364** ^If a suffix is added to the zFilename parameter, it will
1365** consist of a single "-" character followed by no more than
1366** 11 alphanumeric and/or "-" characters.
1367** ^SQLite further guarantees that
1368** the string will be valid and unchanged until xClose() is
1369** called. Because of the previous sentence,
1370** the [sqlite3_file] can safely store a pointer to the
1371** filename if it needs to remember the filename for some reason.
1372** If the zFilename parameter to xOpen is a NULL pointer then xOpen
1373** must invent its own temporary name for the file. ^Whenever the
1374** xFilename parameter is NULL it will also be the case that the
1375** flags parameter will include [SQLITE_OPEN_DELETEONCLOSE].
1376**
1377** The flags argument to xOpen() includes all bits set in
1378** the flags argument to [sqlite3_open_v2()]. Or if [sqlite3_open()]
1379** or [sqlite3_open16()] is used, then flags includes at least
1380** [SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE].
1381** If xOpen() opens a file read-only then it sets *pOutFlags to
1382** include [SQLITE_OPEN_READONLY]. Other bits in *pOutFlags may be set.
1383**
1384** ^(SQLite will also add one of the following flags to the xOpen()
1385** call, depending on the object being opened:
1386**
1387** <ul>
1388** <li> [SQLITE_OPEN_MAIN_DB]
1389** <li> [SQLITE_OPEN_MAIN_JOURNAL]
1390** <li> [SQLITE_OPEN_TEMP_DB]
1391** <li> [SQLITE_OPEN_TEMP_JOURNAL]
1392** <li> [SQLITE_OPEN_TRANSIENT_DB]
1393** <li> [SQLITE_OPEN_SUBJOURNAL]
1394** <li> [SQLITE_OPEN_SUPER_JOURNAL]
1395** <li> [SQLITE_OPEN_WAL]
1396** </ul>)^
1397**
1398** The file I/O implementation can use the object type flags to
1399** change the way it deals with files. For example, an application
1400** that does not care about crash recovery or rollback might make
1401** the open of a journal file a no-op. Writes to this journal would
1402** also be no-ops, and any attempt to read the journal would return
1403** SQLITE_IOERR. Or the implementation might recognize that a database
1404** file will be doing page-aligned sector reads and writes in a random
1405** order and set up its I/O subsystem accordingly.
1406**
1407** SQLite might also add one of the following flags to the xOpen method:
1408**
1409** <ul>
1410** <li> [SQLITE_OPEN_DELETEONCLOSE]
1411** <li> [SQLITE_OPEN_EXCLUSIVE]
1412** </ul>
1413**
1414** The [SQLITE_OPEN_DELETEONCLOSE] flag means the file should be
1415** deleted when it is closed. ^The [SQLITE_OPEN_DELETEONCLOSE]
1416** will be set for TEMP databases and their journals, transient
1417** databases, and subjournals.
1418**
1419** ^The [SQLITE_OPEN_EXCLUSIVE] flag is always used in conjunction
1420** with the [SQLITE_OPEN_CREATE] flag, which are both directly
1421** analogous to the O_EXCL and O_CREAT flags of the POSIX open()
1422** API. The SQLITE_OPEN_EXCLUSIVE flag, when paired with the
1423** SQLITE_OPEN_CREATE, is used to indicate that file should always
1424** be created, and that it is an error if it already exists.
1425** It is <i>not</i> used to indicate the file should be opened
1426** for exclusive access.
1427**
1428** ^At least szOsFile bytes of memory are allocated by SQLite
1429** to hold the [sqlite3_file] structure passed as the third
1430** argument to xOpen. The xOpen method does not have to
1431** allocate the structure; it should just fill it in. Note that
1432** the xOpen method must set the sqlite3_file.pMethods to either
1433** a valid [sqlite3_io_methods] object or to NULL. xOpen must do
1434** this even if the open fails. SQLite expects that the sqlite3_file.pMethods
1435** element will be valid after xOpen returns regardless of the success
1436** or failure of the xOpen call.
1437**
1438** [[sqlite3_vfs.xAccess]]
1439** ^The flags argument to xAccess() may be [SQLITE_ACCESS_EXISTS]
1440** to test for the existence of a file, or [SQLITE_ACCESS_READWRITE] to
1441** test whether a file is readable and writable, or [SQLITE_ACCESS_READ]
1442** to test whether a file is at least readable. The SQLITE_ACCESS_READ
1443** flag is never actually used and is not implemented in the built-in
1444** VFSes of SQLite. The file is named by the second argument and can be a
1445** directory. The xAccess method returns [SQLITE_OK] on success or some
1446** non-zero error code if there is an I/O error or if the name of
1447** the file given in the second argument is illegal. If SQLITE_OK
1448** is returned, then non-zero or zero is written into *pResOut to indicate
1449** whether or not the file is accessible.
1450**
1451** ^SQLite will always allocate at least mxPathname+1 bytes for the
1452** output buffer xFullPathname. The exact size of the output buffer
1453** is also passed as a parameter to both methods. If the output buffer
1454** is not large enough, [SQLITE_CANTOPEN] should be returned. Since this is
1455** handled as a fatal error by SQLite, vfs implementations should endeavor
1456** to prevent this by setting mxPathname to a sufficiently large value.
1457**
1458** The xRandomness(), xSleep(), xCurrentTime(), and xCurrentTimeInt64()
1459** interfaces are not strictly a part of the filesystem, but they are
1460** included in the VFS structure for completeness.
1461** The xRandomness() function attempts to return nBytes bytes
1462** of good-quality randomness into zOut. The return value is
1463** the actual number of bytes of randomness obtained.
1464** The xSleep() method causes the calling thread to sleep for at
1465** least the number of microseconds given. ^The xCurrentTime()
1466** method returns a Julian Day Number for the current date and time as
1467** a floating point value.
1468** ^The xCurrentTimeInt64() method returns, as an integer, the Julian
1469** Day Number multiplied by 86400000 (the number of milliseconds in
1470** a 24-hour day).
1471** ^SQLite will use the xCurrentTimeInt64() method to get the current
1472** date and time if that method is available (if iVersion is 2 or
1473** greater and the function pointer is not NULL) and will fall back
1474** to xCurrentTime() if xCurrentTimeInt64() is unavailable.
1475**
1476** ^The xSetSystemCall(), xGetSystemCall(), and xNestSystemCall() interfaces
1477** are not used by the SQLite core. These optional interfaces are provided
1478** by some VFSes to facilitate testing of the VFS code. By overriding
1479** system calls with functions under its control, a test program can
1480** simulate faults and error conditions that would otherwise be difficult
1481** or impossible to induce. The set of system calls that can be overridden
1482** varies from one VFS to another, and from one version of the same VFS to the
1483** next. Applications that use these interfaces must be prepared for any
1484** or all of these interfaces to be NULL or for their behavior to change
1485** from one release to the next. Applications must not attempt to access
1486** any of these methods if the iVersion of the VFS is less than 3.
1487*/
1488typedef struct sqlite3_vfs sqlite3_vfs;
1489typedef void (*sqlite3_syscall_ptr)(void);
1490struct sqlite3_vfs {
1491 int iVersion; /* Structure version number (currently 3) */
1492 int szOsFile; /* Size of subclassed sqlite3_file */
1493 int mxPathname; /* Maximum file pathname length */
1494 sqlite3_vfs *pNext; /* Next registered VFS */
1495 const char *zName; /* Name of this virtual file system */
1496 void *pAppData; /* Pointer to application-specific data */
1497 int (*xOpen)(sqlite3_vfs*, sqlite3_filename zName, sqlite3_file*,
1498 int flags, int *pOutFlags);
1499 int (*xDelete)(sqlite3_vfs*, const char *zName, int syncDir);
1500 int (*xAccess)(sqlite3_vfs*, const char *zName, int flags, int *pResOut);
1501 int (*xFullPathname)(sqlite3_vfs*, const char *zName, int nOut, char *zOut);
1502 void *(*xDlOpen)(sqlite3_vfs*, const char *zFilename);
1503 void (*xDlError)(sqlite3_vfs*, int nByte, char *zErrMsg);
1504 void (*(*xDlSym)(sqlite3_vfs*,void*, const char *zSymbol))(void);
1505 void (*xDlClose)(sqlite3_vfs*, void*);
1506 int (*xRandomness)(sqlite3_vfs*, int nByte, char *zOut);
1507 int (*xSleep)(sqlite3_vfs*, int microseconds);
1508 int (*xCurrentTime)(sqlite3_vfs*, double*);
1509 int (*xGetLastError)(sqlite3_vfs*, int, char *);
1510 /*
1511 ** The methods above are in version 1 of the sqlite_vfs object
1512 ** definition. Those that follow are added in version 2 or later
1513 */
1514 int (*xCurrentTimeInt64)(sqlite3_vfs*, sqlite3_int64*);
1515 /*
1516 ** The methods above are in versions 1 and 2 of the sqlite_vfs object.
1517 ** Those below are for version 3 and greater.
1518 */
1519 int (*xSetSystemCall)(sqlite3_vfs*, const char *zName, sqlite3_syscall_ptr);
1520 sqlite3_syscall_ptr (*xGetSystemCall)(sqlite3_vfs*, const char *zName);
1521 const char *(*xNextSystemCall)(sqlite3_vfs*, const char *zName);
1522 /*
1523 ** The methods above are in versions 1 through 3 of the sqlite_vfs object.
1524 ** New fields may be appended in future versions. The iVersion
1525 ** value will increment whenever this happens.
1526 */
1527};
1528
1529/*
1530** CAPI3REF: Flags for the xAccess VFS method
1531**
1532** These integer constants can be used as the third parameter to
1533** the xAccess method of an [sqlite3_vfs] object. They determine
1534** what kind of permissions the xAccess method is looking for.
1535** With SQLITE_ACCESS_EXISTS, the xAccess method
1536** simply checks whether the file exists.
1537** With SQLITE_ACCESS_READWRITE, the xAccess method
1538** checks whether the named directory is both readable and writable
1539** (in other words, if files can be added, removed, and renamed within
1540** the directory).
1541** The SQLITE_ACCESS_READWRITE constant is currently used only by the
1542** [temp_store_directory pragma], though this could change in a future
1543** release of SQLite.
1544** With SQLITE_ACCESS_READ, the xAccess method
1545** checks whether the file is readable. The SQLITE_ACCESS_READ constant is
1546** currently unused, though it might be used in a future release of
1547** SQLite.
1548*/
1549#define SQLITE_ACCESS_EXISTS 0
1550#define SQLITE_ACCESS_READWRITE 1 /* Used by PRAGMA temp_store_directory */
1551#define SQLITE_ACCESS_READ 2 /* Unused */
1552
1553/*
1554** CAPI3REF: Flags for the xShmLock VFS method
1555**
1556** These integer constants define the various locking operations
1557** allowed by the xShmLock method of [sqlite3_io_methods]. The
1558** following are the only legal combinations of flags to the
1559** xShmLock method:
1560**
1561** <ul>
1562** <li> SQLITE_SHM_LOCK | SQLITE_SHM_SHARED
1563** <li> SQLITE_SHM_LOCK | SQLITE_SHM_EXCLUSIVE
1564** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_SHARED
1565** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_EXCLUSIVE
1566** </ul>
1567**
1568** When unlocking, the same SHARED or EXCLUSIVE flag must be supplied as
1569** was given on the corresponding lock.
1570**
1571** The xShmLock method can transition between unlocked and SHARED or
1572** between unlocked and EXCLUSIVE. It cannot transition between SHARED
1573** and EXCLUSIVE.
1574*/
1575#define SQLITE_SHM_UNLOCK 1
1576#define SQLITE_SHM_LOCK 2
1577#define SQLITE_SHM_SHARED 4
1578#define SQLITE_SHM_EXCLUSIVE 8
1579
1580/*
1581** CAPI3REF: Maximum xShmLock index
1582**
1583** The xShmLock method on [sqlite3_io_methods] may use values
1584** between 0 and this upper bound as its "offset" argument.
1585** The SQLite core will never attempt to acquire or release a
1586** lock outside of this range
1587*/
1588#define SQLITE_SHM_NLOCK 8
1589
1590
1591/*
1592** CAPI3REF: Initialize The SQLite Library
1593**
1594** ^The sqlite3_initialize() routine initializes the
1595** SQLite library. ^The sqlite3_shutdown() routine
1596** deallocates any resources that were allocated by sqlite3_initialize().
1597** These routines are designed to aid in process initialization and
1598** shutdown on embedded systems. Workstation applications using
1599** SQLite normally do not need to invoke either of these routines.
1600**
1601** A call to sqlite3_initialize() is an "effective" call if it is
1602** the first time sqlite3_initialize() is invoked during the lifetime of
1603** the process, or if it is the first time sqlite3_initialize() is invoked
1604** following a call to sqlite3_shutdown(). ^(Only an effective call
1605** of sqlite3_initialize() does any initialization. All other calls
1606** are harmless no-ops.)^
1607**
1608** A call to sqlite3_shutdown() is an "effective" call if it is the first
1609** call to sqlite3_shutdown() since the last sqlite3_initialize(). ^(Only
1610** an effective call to sqlite3_shutdown() does any deinitialization.
1611** All other valid calls to sqlite3_shutdown() are harmless no-ops.)^
1612**
1613** The sqlite3_initialize() interface is threadsafe, but sqlite3_shutdown()
1614** is not. The sqlite3_shutdown() interface must only be called from a
1615** single thread. All open [database connections] must be closed and all
1616** other SQLite resources must be deallocated prior to invoking
1617** sqlite3_shutdown().
1618**
1619** Among other things, ^sqlite3_initialize() will invoke
1620** sqlite3_os_init(). Similarly, ^sqlite3_shutdown()
1621** will invoke sqlite3_os_end().
1622**
1623** ^The sqlite3_initialize() routine returns [SQLITE_OK] on success.
1624** ^If for some reason, sqlite3_initialize() is unable to initialize
1625** the library (perhaps it is unable to allocate a needed resource such
1626** as a mutex) it returns an [error code] other than [SQLITE_OK].
1627**
1628** ^The sqlite3_initialize() routine is called internally by many other
1629** SQLite interfaces so that an application usually does not need to
1630** invoke sqlite3_initialize() directly. For example, [sqlite3_open()]
1631** calls sqlite3_initialize() so the SQLite library will be automatically
1632** initialized when [sqlite3_open()] is called if it has not be initialized
1633** already. ^However, if SQLite is compiled with the [SQLITE_OMIT_AUTOINIT]
1634** compile-time option, then the automatic calls to sqlite3_initialize()
1635** are omitted and the application must call sqlite3_initialize() directly
1636** prior to using any other SQLite interface. For maximum portability,
1637** it is recommended that applications always invoke sqlite3_initialize()
1638** directly prior to using any other SQLite interface. Future releases
1639** of SQLite may require this. In other words, the behavior exhibited
1640** when SQLite is compiled with [SQLITE_OMIT_AUTOINIT] might become the
1641** default behavior in some future release of SQLite.
1642**
1643** The sqlite3_os_init() routine does operating-system specific
1644** initialization of the SQLite library. The sqlite3_os_end()
1645** routine undoes the effect of sqlite3_os_init(). Typical tasks
1646** performed by these routines include allocation or deallocation
1647** of static resources, initialization of global variables,
1648** setting up a default [sqlite3_vfs] module, or setting up
1649** a default configuration using [sqlite3_config()].
1650**
1651** The application should never invoke either sqlite3_os_init()
1652** or sqlite3_os_end() directly. The application should only invoke
1653** sqlite3_initialize() and sqlite3_shutdown(). The sqlite3_os_init()
1654** interface is called automatically by sqlite3_initialize() and
1655** sqlite3_os_end() is called by sqlite3_shutdown(). Appropriate
1656** implementations for sqlite3_os_init() and sqlite3_os_end()
1657** are built into SQLite when it is compiled for Unix, Windows, or OS/2.
1658** When [custom builds | built for other platforms]
1659** (using the [SQLITE_OS_OTHER=1] compile-time
1660** option) the application must supply a suitable implementation for
1661** sqlite3_os_init() and sqlite3_os_end(). An application-supplied
1662** implementation of sqlite3_os_init() or sqlite3_os_end()
1663** must return [SQLITE_OK] on success and some other [error code] upon
1664** failure.
1665*/
1666SQLITE_API int sqlite3_initialize(void);
1667SQLITE_API int sqlite3_shutdown(void);
1668SQLITE_API int sqlite3_os_init(void);
1669SQLITE_API int sqlite3_os_end(void);
1670
1671/*
1672** CAPI3REF: Configuring The SQLite Library
1673**
1674** The sqlite3_config() interface is used to make global configuration
1675** changes to SQLite in order to tune SQLite to the specific needs of
1676** the application. The default configuration is recommended for most
1677** applications and so this routine is usually not necessary. It is
1678** provided to support rare applications with unusual needs.
1679**
1680** <b>The sqlite3_config() interface is not threadsafe. The application
1681** must ensure that no other SQLite interfaces are invoked by other
1682** threads while sqlite3_config() is running.</b>
1683**
1684** The first argument to sqlite3_config() is an integer
1685** [configuration option] that determines
1686** what property of SQLite is to be configured. Subsequent arguments
1687** vary depending on the [configuration option]
1688** in the first argument.
1689**
1690** For most configuration options, the sqlite3_config() interface
1691** may only be invoked prior to library initialization using
1692** [sqlite3_initialize()] or after shutdown by [sqlite3_shutdown()].
1693** The exceptional configuration options that may be invoked at any time
1694** are called "anytime configuration options".
1695** ^If sqlite3_config() is called after [sqlite3_initialize()] and before
1696** [sqlite3_shutdown()] with a first argument that is not an anytime
1697** configuration option, then the sqlite3_config() call will return SQLITE_MISUSE.
1698** Note, however, that ^sqlite3_config() can be called as part of the
1699** implementation of an application-defined [sqlite3_os_init()].
1700**
1701** ^When a configuration option is set, sqlite3_config() returns [SQLITE_OK].
1702** ^If the option is unknown or SQLite is unable to set the option
1703** then this routine returns a non-zero [error code].
1704*/
1705SQLITE_API int sqlite3_config(int, ...);
1706
1707/*
1708** CAPI3REF: Configure database connections
1709** METHOD: sqlite3
1710**
1711** The sqlite3_db_config() interface is used to make configuration
1712** changes to a [database connection]. The interface is similar to
1713** [sqlite3_config()] except that the changes apply to a single
1714** [database connection] (specified in the first argument).
1715**
1716** The second argument to sqlite3_db_config(D,V,...) is the
1717** [SQLITE_DBCONFIG_LOOKASIDE | configuration verb] - an integer code
1718** that indicates what aspect of the [database connection] is being configured.
1719** Subsequent arguments vary depending on the configuration verb.
1720**
1721** ^Calls to sqlite3_db_config() return SQLITE_OK if and only if
1722** the call is considered successful.
1723*/
1724SQLITE_API int sqlite3_db_config(sqlite3*, int op, ...);
1725
1726/*
1727** CAPI3REF: Memory Allocation Routines
1728**
1729** An instance of this object defines the interface between SQLite
1730** and low-level memory allocation routines.
1731**
1732** This object is used in only one place in the SQLite interface.
1733** A pointer to an instance of this object is the argument to
1734** [sqlite3_config()] when the configuration option is
1735** [SQLITE_CONFIG_MALLOC] or [SQLITE_CONFIG_GETMALLOC].
1736** By creating an instance of this object
1737** and passing it to [sqlite3_config]([SQLITE_CONFIG_MALLOC])
1738** during configuration, an application can specify an alternative
1739** memory allocation subsystem for SQLite to use for all of its
1740** dynamic memory needs.
1741**
1742** Note that SQLite comes with several [built-in memory allocators]
1743** that are perfectly adequate for the overwhelming majority of applications
1744** and that this object is only useful to a tiny minority of applications
1745** with specialized memory allocation requirements. This object is
1746** also used during testing of SQLite in order to specify an alternative
1747** memory allocator that simulates memory out-of-memory conditions in
1748** order to verify that SQLite recovers gracefully from such
1749** conditions.
1750**
1751** The xMalloc, xRealloc, and xFree methods must work like the
1752** malloc(), realloc() and free() functions from the standard C library.
1753** ^SQLite guarantees that the second argument to
1754** xRealloc is always a value returned by a prior call to xRoundup.
1755**
1756** xSize should return the allocated size of a memory allocation
1757** previously obtained from xMalloc or xRealloc. The allocated size
1758** is always at least as big as the requested size but may be larger.
1759**
1760** The xRoundup method returns what would be the allocated size of
1761** a memory allocation given a particular requested size. Most memory
1762** allocators round up memory allocations at least to the next multiple
1763** of 8. Some allocators round up to a larger multiple or to a power of 2.
1764** Every memory allocation request coming in through [sqlite3_malloc()]
1765** or [sqlite3_realloc()] first calls xRoundup. If xRoundup returns 0,
1766** that causes the corresponding memory allocation to fail.
1767**
1768** The xInit method initializes the memory allocator. For example,
1769** it might allocate any required mutexes or initialize internal data
1770** structures. The xShutdown method is invoked (indirectly) by
1771** [sqlite3_shutdown()] and should deallocate any resources acquired
1772** by xInit. The pAppData pointer is used as the only parameter to
1773** xInit and xShutdown.
1774**
1775** SQLite holds the [SQLITE_MUTEX_STATIC_MAIN] mutex when it invokes
1776** the xInit method, so the xInit method need not be threadsafe. The
1777** xShutdown method is only called from [sqlite3_shutdown()] so it does
1778** not need to be threadsafe either. For all other methods, SQLite
1779** holds the [SQLITE_MUTEX_STATIC_MEM] mutex as long as the
1780** [SQLITE_CONFIG_MEMSTATUS] configuration option is turned on (which
1781** it is by default) and so the methods are automatically serialized.
1782** However, if [SQLITE_CONFIG_MEMSTATUS] is disabled, then the other
1783** methods must be threadsafe or else make their own arrangements for
1784** serialization.
1785**
1786** SQLite will never invoke xInit() more than once without an intervening
1787** call to xShutdown().
1788*/
1789typedef struct sqlite3_mem_methods sqlite3_mem_methods;
1790struct sqlite3_mem_methods {
1791 void *(*xMalloc)(int); /* Memory allocation function */
1792 void (*xFree)(void*); /* Free a prior allocation */
1793 void *(*xRealloc)(void*,int); /* Resize an allocation */
1794 int (*xSize)(void*); /* Return the size of an allocation */
1795 int (*xRoundup)(int); /* Round up request size to allocation size */
1796 int (*xInit)(void*); /* Initialize the memory allocator */
1797 void (*xShutdown)(void*); /* Deinitialize the memory allocator */
1798 void *pAppData; /* Argument to xInit() and xShutdown() */
1799};
1800
1801/*
1802** CAPI3REF: Configuration Options
1803** KEYWORDS: {configuration option}
1804**
1805** These constants are the available integer configuration options that
1806** can be passed as the first argument to the [sqlite3_config()] interface.
1807**
1808** Most of the configuration options for sqlite3_config()
1809** will only work if invoked prior to [sqlite3_initialize()] or after
1810** [sqlite3_shutdown()]. The few exceptions to this rule are called
1811** "anytime configuration options".
1812** ^Calling [sqlite3_config()] with a first argument that is not an
1813** anytime configuration option in between calls to [sqlite3_initialize()] and
1814** [sqlite3_shutdown()] is a no-op that returns SQLITE_MISUSE.
1815**
1816** The set of anytime configuration options can change (by insertions
1817** and/or deletions) from one release of SQLite to the next.
1818** As of SQLite version 3.42.0, the complete set of anytime configuration
1819** options is:
1820** <ul>
1821** <li> SQLITE_CONFIG_LOG
1822** <li> SQLITE_CONFIG_PCACHE_HDRSZ
1823** </ul>
1824**
1825** New configuration options may be added in future releases of SQLite.
1826** Existing configuration options might be discontinued. Applications
1827** should check the return code from [sqlite3_config()] to make sure that
1828** the call worked. The [sqlite3_config()] interface will return a
1829** non-zero [error code] if a discontinued or unsupported configuration option
1830** is invoked.
1831**
1832** <dl>
1833** [[SQLITE_CONFIG_SINGLETHREAD]] <dt>SQLITE_CONFIG_SINGLETHREAD</dt>
1834** <dd>There are no arguments to this option. ^This option sets the
1835** [threading mode] to Single-thread. In other words, it disables
1836** all mutexing and puts SQLite into a mode where it can only be used
1837** by a single thread. ^If SQLite is compiled with
1838** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
1839** it is not possible to change the [threading mode] from its default
1840** value of Single-thread and so [sqlite3_config()] will return
1841** [SQLITE_ERROR] if called with the SQLITE_CONFIG_SINGLETHREAD
1842** configuration option.</dd>
1843**
1844** [[SQLITE_CONFIG_MULTITHREAD]] <dt>SQLITE_CONFIG_MULTITHREAD</dt>
1845** <dd>There are no arguments to this option. ^This option sets the
1846** [threading mode] to Multi-thread. In other words, it disables
1847** mutexing on [database connection] and [prepared statement] objects.
1848** The application is responsible for serializing access to
1849** [database connections] and [prepared statements]. But other mutexes
1850** are enabled so that SQLite will be safe to use in a multi-threaded
1851** environment as long as no two threads attempt to use the same
1852** [database connection] at the same time. ^If SQLite is compiled with
1853** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
1854** it is not possible to set the Multi-thread [threading mode] and
1855** [sqlite3_config()] will return [SQLITE_ERROR] if called with the
1856** SQLITE_CONFIG_MULTITHREAD configuration option.</dd>
1857**
1858** [[SQLITE_CONFIG_SERIALIZED]] <dt>SQLITE_CONFIG_SERIALIZED</dt>
1859** <dd>There are no arguments to this option. ^This option sets the
1860** [threading mode] to Serialized. In other words, this option enables
1861** all mutexes including the recursive
1862** mutexes on [database connection] and [prepared statement] objects.
1863** In this mode (which is the default when SQLite is compiled with
1864** [SQLITE_THREADSAFE=1]) the SQLite library will itself serialize access
1865** to [database connections] and [prepared statements] so that the
1866** application is free to use the same [database connection] or the
1867** same [prepared statement] in different threads at the same time.
1868** ^If SQLite is compiled with
1869** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
1870** it is not possible to set the Serialized [threading mode] and
1871** [sqlite3_config()] will return [SQLITE_ERROR] if called with the
1872** SQLITE_CONFIG_SERIALIZED configuration option.</dd>
1873**
1874** [[SQLITE_CONFIG_MALLOC]] <dt>SQLITE_CONFIG_MALLOC</dt>
1875** <dd> ^(The SQLITE_CONFIG_MALLOC option takes a single argument which is
1876** a pointer to an instance of the [sqlite3_mem_methods] structure.
1877** The argument specifies
1878** alternative low-level memory allocation routines to be used in place of
1879** the memory allocation routines built into SQLite.)^ ^SQLite makes
1880** its own private copy of the content of the [sqlite3_mem_methods] structure
1881** before the [sqlite3_config()] call returns.</dd>
1882**
1883** [[SQLITE_CONFIG_GETMALLOC]] <dt>SQLITE_CONFIG_GETMALLOC</dt>
1884** <dd> ^(The SQLITE_CONFIG_GETMALLOC option takes a single argument which
1885** is a pointer to an instance of the [sqlite3_mem_methods] structure.
1886** The [sqlite3_mem_methods]
1887** structure is filled with the currently defined memory allocation routines.)^
1888** This option can be used to overload the default memory allocation
1889** routines with a wrapper that simulations memory allocation failure or
1890** tracks memory usage, for example. </dd>
1891**
1892** [[SQLITE_CONFIG_SMALL_MALLOC]] <dt>SQLITE_CONFIG_SMALL_MALLOC</dt>
1893** <dd> ^The SQLITE_CONFIG_SMALL_MALLOC option takes single argument of
1894** type int, interpreted as a boolean, which if true provides a hint to
1895** SQLite that it should avoid large memory allocations if possible.
1896** SQLite will run faster if it is free to make large memory allocations,
1897** but some application might prefer to run slower in exchange for
1898** guarantees about memory fragmentation that are possible if large
1899** allocations are avoided. This hint is normally off.
1900** </dd>
1901**
1902** [[SQLITE_CONFIG_MEMSTATUS]] <dt>SQLITE_CONFIG_MEMSTATUS</dt>
1903** <dd> ^The SQLITE_CONFIG_MEMSTATUS option takes single argument of type int,
1904** interpreted as a boolean, which enables or disables the collection of
1905** memory allocation statistics. ^(When memory allocation statistics are
1906** disabled, the following SQLite interfaces become non-operational:
1907** <ul>
1908** <li> [sqlite3_hard_heap_limit64()]
1909** <li> [sqlite3_memory_used()]
1910** <li> [sqlite3_memory_highwater()]
1911** <li> [sqlite3_soft_heap_limit64()]
1912** <li> [sqlite3_status64()]
1913** </ul>)^
1914** ^Memory allocation statistics are enabled by default unless SQLite is
1915** compiled with [SQLITE_DEFAULT_MEMSTATUS]=0 in which case memory
1916** allocation statistics are disabled by default.
1917** </dd>
1918**
1919** [[SQLITE_CONFIG_SCRATCH]] <dt>SQLITE_CONFIG_SCRATCH</dt>
1920** <dd> The SQLITE_CONFIG_SCRATCH option is no longer used.
1921** </dd>
1922**
1923** [[SQLITE_CONFIG_PAGECACHE]] <dt>SQLITE_CONFIG_PAGECACHE</dt>
1924** <dd> ^The SQLITE_CONFIG_PAGECACHE option specifies a memory pool
1925** that SQLite can use for the database page cache with the default page
1926** cache implementation.
1927** This configuration option is a no-op if an application-defined page
1928** cache implementation is loaded using the [SQLITE_CONFIG_PCACHE2].
1929** ^There are three arguments to SQLITE_CONFIG_PAGECACHE: A pointer to
1930** 8-byte aligned memory (pMem), the size of each page cache line (sz),
1931** and the number of cache lines (N).
1932** The sz argument should be the size of the largest database page
1933** (a power of two between 512 and 65536) plus some extra bytes for each
1934** page header. ^The number of extra bytes needed by the page header
1935** can be determined using [SQLITE_CONFIG_PCACHE_HDRSZ].
1936** ^It is harmless, apart from the wasted memory,
1937** for the sz parameter to be larger than necessary. The pMem
1938** argument must be either a NULL pointer or a pointer to an 8-byte
1939** aligned block of memory of at least sz*N bytes, otherwise
1940** subsequent behavior is undefined.
1941** ^When pMem is not NULL, SQLite will strive to use the memory provided
1942** to satisfy page cache needs, falling back to [sqlite3_malloc()] if
1943** a page cache line is larger than sz bytes or if all of the pMem buffer
1944** is exhausted.
1945** ^If pMem is NULL and N is non-zero, then each database connection
1946** does an initial bulk allocation for page cache memory
1947** from [sqlite3_malloc()] sufficient for N cache lines if N is positive or
1948** of -1024*N bytes if N is negative, . ^If additional
1949** page cache memory is needed beyond what is provided by the initial
1950** allocation, then SQLite goes to [sqlite3_malloc()] separately for each
1951** additional cache line. </dd>
1952**
1953** [[SQLITE_CONFIG_HEAP]] <dt>SQLITE_CONFIG_HEAP</dt>
1954** <dd> ^The SQLITE_CONFIG_HEAP option specifies a static memory buffer
1955** that SQLite will use for all of its dynamic memory allocation needs
1956** beyond those provided for by [SQLITE_CONFIG_PAGECACHE].
1957** ^The SQLITE_CONFIG_HEAP option is only available if SQLite is compiled
1958** with either [SQLITE_ENABLE_MEMSYS3] or [SQLITE_ENABLE_MEMSYS5] and returns
1959** [SQLITE_ERROR] if invoked otherwise.
1960** ^There are three arguments to SQLITE_CONFIG_HEAP:
1961** An 8-byte aligned pointer to the memory,
1962** the number of bytes in the memory buffer, and the minimum allocation size.
1963** ^If the first pointer (the memory pointer) is NULL, then SQLite reverts
1964** to using its default memory allocator (the system malloc() implementation),
1965** undoing any prior invocation of [SQLITE_CONFIG_MALLOC]. ^If the
1966** memory pointer is not NULL then the alternative memory
1967** allocator is engaged to handle all of SQLites memory allocation needs.
1968** The first pointer (the memory pointer) must be aligned to an 8-byte
1969** boundary or subsequent behavior of SQLite will be undefined.
1970** The minimum allocation size is capped at 2**12. Reasonable values
1971** for the minimum allocation size are 2**5 through 2**8.</dd>
1972**
1973** [[SQLITE_CONFIG_MUTEX]] <dt>SQLITE_CONFIG_MUTEX</dt>
1974** <dd> ^(The SQLITE_CONFIG_MUTEX option takes a single argument which is a
1975** pointer to an instance of the [sqlite3_mutex_methods] structure.
1976** The argument specifies alternative low-level mutex routines to be used
1977** in place the mutex routines built into SQLite.)^ ^SQLite makes a copy of
1978** the content of the [sqlite3_mutex_methods] structure before the call to
1979** [sqlite3_config()] returns. ^If SQLite is compiled with
1980** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
1981** the entire mutexing subsystem is omitted from the build and hence calls to
1982** [sqlite3_config()] with the SQLITE_CONFIG_MUTEX configuration option will
1983** return [SQLITE_ERROR].</dd>
1984**
1985** [[SQLITE_CONFIG_GETMUTEX]] <dt>SQLITE_CONFIG_GETMUTEX</dt>
1986** <dd> ^(The SQLITE_CONFIG_GETMUTEX option takes a single argument which
1987** is a pointer to an instance of the [sqlite3_mutex_methods] structure. The
1988** [sqlite3_mutex_methods]
1989** structure is filled with the currently defined mutex routines.)^
1990** This option can be used to overload the default mutex allocation
1991** routines with a wrapper used to track mutex usage for performance
1992** profiling or testing, for example. ^If SQLite is compiled with
1993** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
1994** the entire mutexing subsystem is omitted from the build and hence calls to
1995** [sqlite3_config()] with the SQLITE_CONFIG_GETMUTEX configuration option will
1996** return [SQLITE_ERROR].</dd>
1997**
1998** [[SQLITE_CONFIG_LOOKASIDE]] <dt>SQLITE_CONFIG_LOOKASIDE</dt>
1999** <dd> ^(The SQLITE_CONFIG_LOOKASIDE option takes two arguments that determine
2000** the default size of [lookaside memory] on each [database connection].
2001** The first argument is the
2002** size of each lookaside buffer slot ("sz") and the second is the number of
2003** slots allocated to each database connection ("cnt").)^
2004** ^(SQLITE_CONFIG_LOOKASIDE sets the <i>default</i> lookaside size.
2005** The [SQLITE_DBCONFIG_LOOKASIDE] option to [sqlite3_db_config()] can
2006** be used to change the lookaside configuration on individual connections.)^
2007** The [-DSQLITE_DEFAULT_LOOKASIDE] option can be used to change the
2008** default lookaside configuration at compile-time.
2009** </dd>
2010**
2011** [[SQLITE_CONFIG_PCACHE2]] <dt>SQLITE_CONFIG_PCACHE2</dt>
2012** <dd> ^(The SQLITE_CONFIG_PCACHE2 option takes a single argument which is
2013** a pointer to an [sqlite3_pcache_methods2] object. This object specifies
2014** the interface to a custom page cache implementation.)^
2015** ^SQLite makes a copy of the [sqlite3_pcache_methods2] object.</dd>
2016**
2017** [[SQLITE_CONFIG_GETPCACHE2]] <dt>SQLITE_CONFIG_GETPCACHE2</dt>
2018** <dd> ^(The SQLITE_CONFIG_GETPCACHE2 option takes a single argument which
2019** is a pointer to an [sqlite3_pcache_methods2] object. SQLite copies of
2020** the current page cache implementation into that object.)^ </dd>
2021**
2022** [[SQLITE_CONFIG_LOG]] <dt>SQLITE_CONFIG_LOG</dt>
2023** <dd> The SQLITE_CONFIG_LOG option is used to configure the SQLite
2024** global [error log].
2025** (^The SQLITE_CONFIG_LOG option takes two arguments: a pointer to a
2026** function with a call signature of void(*)(void*,int,const char*),
2027** and a pointer to void. ^If the function pointer is not NULL, it is
2028** invoked by [sqlite3_log()] to process each logging event. ^If the
2029** function pointer is NULL, the [sqlite3_log()] interface becomes a no-op.
2030** ^The void pointer that is the second argument to SQLITE_CONFIG_LOG is
2031** passed through as the first parameter to the application-defined logger
2032** function whenever that function is invoked. ^The second parameter to
2033** the logger function is a copy of the first parameter to the corresponding
2034** [sqlite3_log()] call and is intended to be a [result code] or an
2035** [extended result code]. ^The third parameter passed to the logger is
2036** log message after formatting via [sqlite3_snprintf()].
2037** The SQLite logging interface is not reentrant; the logger function
2038** supplied by the application must not invoke any SQLite interface.
2039** In a multi-threaded application, the application-defined logger
2040** function must be threadsafe. </dd>
2041**
2042** [[SQLITE_CONFIG_URI]] <dt>SQLITE_CONFIG_URI
2043** <dd>^(The SQLITE_CONFIG_URI option takes a single argument of type int.
2044** If non-zero, then URI handling is globally enabled. If the parameter is zero,
2045** then URI handling is globally disabled.)^ ^If URI handling is globally
2046** enabled, all filenames passed to [sqlite3_open()], [sqlite3_open_v2()],
2047** [sqlite3_open16()] or
2048** specified as part of [ATTACH] commands are interpreted as URIs, regardless
2049** of whether or not the [SQLITE_OPEN_URI] flag is set when the database
2050** connection is opened. ^If it is globally disabled, filenames are
2051** only interpreted as URIs if the SQLITE_OPEN_URI flag is set when the
2052** database connection is opened. ^(By default, URI handling is globally
2053** disabled. The default value may be changed by compiling with the
2054** [SQLITE_USE_URI] symbol defined.)^
2055**
2056** [[SQLITE_CONFIG_COVERING_INDEX_SCAN]] <dt>SQLITE_CONFIG_COVERING_INDEX_SCAN
2057** <dd>^The SQLITE_CONFIG_COVERING_INDEX_SCAN option takes a single integer
2058** argument which is interpreted as a boolean in order to enable or disable
2059** the use of covering indices for full table scans in the query optimizer.
2060** ^The default setting is determined
2061** by the [SQLITE_ALLOW_COVERING_INDEX_SCAN] compile-time option, or is "on"
2062** if that compile-time option is omitted.
2063** The ability to disable the use of covering indices for full table scans
2064** is because some incorrectly coded legacy applications might malfunction
2065** when the optimization is enabled. Providing the ability to
2066** disable the optimization allows the older, buggy application code to work
2067** without change even with newer versions of SQLite.
2068**
2069** [[SQLITE_CONFIG_PCACHE]] [[SQLITE_CONFIG_GETPCACHE]]
2070** <dt>SQLITE_CONFIG_PCACHE and SQLITE_CONFIG_GETPCACHE
2071** <dd> These options are obsolete and should not be used by new code.
2072** They are retained for backwards compatibility but are now no-ops.
2073** </dd>
2074**
2075** [[SQLITE_CONFIG_SQLLOG]]
2076** <dt>SQLITE_CONFIG_SQLLOG
2077** <dd>This option is only available if sqlite is compiled with the
2078** [SQLITE_ENABLE_SQLLOG] pre-processor macro defined. The first argument should
2079** be a pointer to a function of type void(*)(void*,sqlite3*,const char*, int).
2080** The second should be of type (void*). The callback is invoked by the library
2081** in three separate circumstances, identified by the value passed as the
2082** fourth parameter. If the fourth parameter is 0, then the database connection
2083** passed as the second argument has just been opened. The third argument
2084** points to a buffer containing the name of the main database file. If the
2085** fourth parameter is 1, then the SQL statement that the third parameter
2086** points to has just been executed. Or, if the fourth parameter is 2, then
2087** the connection being passed as the second parameter is being closed. The
2088** third parameter is passed NULL In this case. An example of using this
2089** configuration option can be seen in the "test_sqllog.c" source file in
2090** the canonical SQLite source tree.</dd>
2091**
2092** [[SQLITE_CONFIG_MMAP_SIZE]]
2093** <dt>SQLITE_CONFIG_MMAP_SIZE
2094** <dd>^SQLITE_CONFIG_MMAP_SIZE takes two 64-bit integer (sqlite3_int64) values
2095** that are the default mmap size limit (the default setting for
2096** [PRAGMA mmap_size]) and the maximum allowed mmap size limit.
2097** ^The default setting can be overridden by each database connection using
2098** either the [PRAGMA mmap_size] command, or by using the
2099** [SQLITE_FCNTL_MMAP_SIZE] file control. ^(The maximum allowed mmap size
2100** will be silently truncated if necessary so that it does not exceed the
2101** compile-time maximum mmap size set by the
2102** [SQLITE_MAX_MMAP_SIZE] compile-time option.)^
2103** ^If either argument to this option is negative, then that argument is
2104** changed to its compile-time default.
2105**
2106** [[SQLITE_CONFIG_WIN32_HEAPSIZE]]
2107** <dt>SQLITE_CONFIG_WIN32_HEAPSIZE
2108** <dd>^The SQLITE_CONFIG_WIN32_HEAPSIZE option is only available if SQLite is
2109** compiled for Windows with the [SQLITE_WIN32_MALLOC] pre-processor macro
2110** defined. ^SQLITE_CONFIG_WIN32_HEAPSIZE takes a 32-bit unsigned integer value
2111** that specifies the maximum size of the created heap.
2112**
2113** [[SQLITE_CONFIG_PCACHE_HDRSZ]]
2114** <dt>SQLITE_CONFIG_PCACHE_HDRSZ
2115** <dd>^The SQLITE_CONFIG_PCACHE_HDRSZ option takes a single parameter which
2116** is a pointer to an integer and writes into that integer the number of extra
2117** bytes per page required for each page in [SQLITE_CONFIG_PAGECACHE].
2118** The amount of extra space required can change depending on the compiler,
2119** target platform, and SQLite version.
2120**
2121** [[SQLITE_CONFIG_PMASZ]]
2122** <dt>SQLITE_CONFIG_PMASZ
2123** <dd>^The SQLITE_CONFIG_PMASZ option takes a single parameter which
2124** is an unsigned integer and sets the "Minimum PMA Size" for the multithreaded
2125** sorter to that integer. The default minimum PMA Size is set by the
2126** [SQLITE_SORTER_PMASZ] compile-time option. New threads are launched
2127** to help with sort operations when multithreaded sorting
2128** is enabled (using the [PRAGMA threads] command) and the amount of content
2129** to be sorted exceeds the page size times the minimum of the
2130** [PRAGMA cache_size] setting and this value.
2131**
2132** [[SQLITE_CONFIG_STMTJRNL_SPILL]]
2133** <dt>SQLITE_CONFIG_STMTJRNL_SPILL
2134** <dd>^The SQLITE_CONFIG_STMTJRNL_SPILL option takes a single parameter which
2135** becomes the [statement journal] spill-to-disk threshold.
2136** [Statement journals] are held in memory until their size (in bytes)
2137** exceeds this threshold, at which point they are written to disk.
2138** Or if the threshold is -1, statement journals are always held
2139** exclusively in memory.
2140** Since many statement journals never become large, setting the spill
2141** threshold to a value such as 64KiB can greatly reduce the amount of
2142** I/O required to support statement rollback.
2143** The default value for this setting is controlled by the
2144** [SQLITE_STMTJRNL_SPILL] compile-time option.
2145**
2146** [[SQLITE_CONFIG_SORTERREF_SIZE]]
2147** <dt>SQLITE_CONFIG_SORTERREF_SIZE
2148** <dd>The SQLITE_CONFIG_SORTERREF_SIZE option accepts a single parameter
2149** of type (int) - the new value of the sorter-reference size threshold.
2150** Usually, when SQLite uses an external sort to order records according
2151** to an ORDER BY clause, all fields required by the caller are present in the
2152** sorted records. However, if SQLite determines based on the declared type
2153** of a table column that its values are likely to be very large - larger
2154** than the configured sorter-reference size threshold - then a reference
2155** is stored in each sorted record and the required column values loaded
2156** from the database as records are returned in sorted order. The default
2157** value for this option is to never use this optimization. Specifying a
2158** negative value for this option restores the default behavior.
2159** This option is only available if SQLite is compiled with the
2160** [SQLITE_ENABLE_SORTER_REFERENCES] compile-time option.
2161**
2162** [[SQLITE_CONFIG_MEMDB_MAXSIZE]]
2163** <dt>SQLITE_CONFIG_MEMDB_MAXSIZE
2164** <dd>The SQLITE_CONFIG_MEMDB_MAXSIZE option accepts a single parameter
2165** [sqlite3_int64] parameter which is the default maximum size for an in-memory
2166** database created using [sqlite3_deserialize()]. This default maximum
2167** size can be adjusted up or down for individual databases using the
2168** [SQLITE_FCNTL_SIZE_LIMIT] [sqlite3_file_control|file-control]. If this
2169** configuration setting is never used, then the default maximum is determined
2170** by the [SQLITE_MEMDB_DEFAULT_MAXSIZE] compile-time option. If that
2171** compile-time option is not set, then the default maximum is 1073741824.
2172**
2173** [[SQLITE_CONFIG_ROWID_IN_VIEW]]
2174** <dt>SQLITE_CONFIG_ROWID_IN_VIEW
2175** <dd>The SQLITE_CONFIG_ROWID_IN_VIEW option enables or disables the ability
2176** for VIEWs to have a ROWID. The capability can only be enabled if SQLite is
2177** compiled with -DSQLITE_ALLOW_ROWID_IN_VIEW, in which case the capability
2178** defaults to on. This configuration option queries the current setting or
2179** changes the setting to off or on. The argument is a pointer to an integer.
2180** If that integer initially holds a value of 1, then the ability for VIEWs to
2181** have ROWIDs is activated. If the integer initially holds zero, then the
2182** ability is deactivated. Any other initial value for the integer leaves the
2183** setting unchanged. After changes, if any, the integer is written with
2184** a 1 or 0, if the ability for VIEWs to have ROWIDs is on or off. If SQLite
2185** is compiled without -DSQLITE_ALLOW_ROWID_IN_VIEW (which is the usual and
2186** recommended case) then the integer is always filled with zero, regardless
2187** if its initial value.
2188** </dl>
2189*/
2190#define SQLITE_CONFIG_SINGLETHREAD 1 /* nil */
2191#define SQLITE_CONFIG_MULTITHREAD 2 /* nil */
2192#define SQLITE_CONFIG_SERIALIZED 3 /* nil */
2193#define SQLITE_CONFIG_MALLOC 4 /* sqlite3_mem_methods* */
2194#define SQLITE_CONFIG_GETMALLOC 5 /* sqlite3_mem_methods* */
2195#define SQLITE_CONFIG_SCRATCH 6 /* No longer used */
2196#define SQLITE_CONFIG_PAGECACHE 7 /* void*, int sz, int N */
2197#define SQLITE_CONFIG_HEAP 8 /* void*, int nByte, int min */
2198#define SQLITE_CONFIG_MEMSTATUS 9 /* boolean */
2199#define SQLITE_CONFIG_MUTEX 10 /* sqlite3_mutex_methods* */
2200#define SQLITE_CONFIG_GETMUTEX 11 /* sqlite3_mutex_methods* */
2201/* previously SQLITE_CONFIG_CHUNKALLOC 12 which is now unused. */
2202#define SQLITE_CONFIG_LOOKASIDE 13 /* int int */
2203#define SQLITE_CONFIG_PCACHE 14 /* no-op */
2204#define SQLITE_CONFIG_GETPCACHE 15 /* no-op */
2205#define SQLITE_CONFIG_LOG 16 /* xFunc, void* */
2206#define SQLITE_CONFIG_URI 17 /* int */
2207#define SQLITE_CONFIG_PCACHE2 18 /* sqlite3_pcache_methods2* */
2208#define SQLITE_CONFIG_GETPCACHE2 19 /* sqlite3_pcache_methods2* */
2209#define SQLITE_CONFIG_COVERING_INDEX_SCAN 20 /* int */
2210#define SQLITE_CONFIG_SQLLOG 21 /* xSqllog, void* */
2211#define SQLITE_CONFIG_MMAP_SIZE 22 /* sqlite3_int64, sqlite3_int64 */
2212#define SQLITE_CONFIG_WIN32_HEAPSIZE 23 /* int nByte */
2213#define SQLITE_CONFIG_PCACHE_HDRSZ 24 /* int *psz */
2214#define SQLITE_CONFIG_PMASZ 25 /* unsigned int szPma */
2215#define SQLITE_CONFIG_STMTJRNL_SPILL 26 /* int nByte */
2216#define SQLITE_CONFIG_SMALL_MALLOC 27 /* boolean */
2217#define SQLITE_CONFIG_SORTERREF_SIZE 28 /* int nByte */
2218#define SQLITE_CONFIG_MEMDB_MAXSIZE 29 /* sqlite3_int64 */
2219#define SQLITE_CONFIG_ROWID_IN_VIEW 30 /* int* */
2220
2221/*
2222** CAPI3REF: Database Connection Configuration Options
2223**
2224** These constants are the available integer configuration options that
2225** can be passed as the second parameter to the [sqlite3_db_config()] interface.
2226**
2227** The [sqlite3_db_config()] interface is a var-args functions. It takes a
2228** variable number of parameters, though always at least two. The number of
2229** parameters passed into sqlite3_db_config() depends on which of these
2230** constants is given as the second parameter. This documentation page
2231** refers to parameters beyond the second as "arguments". Thus, when this
2232** page says "the N-th argument" it means "the N-th parameter past the
2233** configuration option" or "the (N+2)-th parameter to sqlite3_db_config()".
2234**
2235** New configuration options may be added in future releases of SQLite.
2236** Existing configuration options might be discontinued. Applications
2237** should check the return code from [sqlite3_db_config()] to make sure that
2238** the call worked. ^The [sqlite3_db_config()] interface will return a
2239** non-zero [error code] if a discontinued or unsupported configuration option
2240** is invoked.
2241**
2242** <dl>
2243** [[SQLITE_DBCONFIG_LOOKASIDE]]
2244** <dt>SQLITE_DBCONFIG_LOOKASIDE</dt>
2245** <dd> The SQLITE_DBCONFIG_LOOKASIDE option is used to adjust the
2246** configuration of the [lookaside memory allocator] within a database
2247** connection.
2248** The arguments to the SQLITE_DBCONFIG_LOOKASIDE option are <i>not</i>
2249** in the [DBCONFIG arguments|usual format].
2250** The SQLITE_DBCONFIG_LOOKASIDE option takes three arguments, not two,
2251** so that a call to [sqlite3_db_config()] that uses SQLITE_DBCONFIG_LOOKASIDE
2252** should have a total of five parameters.
2253** <ol>
2254** <li><p>The first argument ("buf") is a
2255** pointer to a memory buffer to use for lookaside memory.
2256** The first argument may be NULL in which case SQLite will allocate the
2257** lookaside buffer itself using [sqlite3_malloc()].
2258** <li><P>The second argument ("sz") is the
2259** size of each lookaside buffer slot. Lookaside is disabled if "sz"
2260** is less than 8. The "sz" argument should be a multiple of 8 less than
2261** 65536. If "sz" does not meet this constraint, it is reduced in size until
2262** it does.
2263** <li><p>The third argument ("cnt") is the number of slots. Lookaside is disabled
2264** if "cnt"is less than 1. The "cnt" value will be reduced, if necessary, so
2265** that the product of "sz" and "cnt" does not exceed 2,147,418,112. The "cnt"
2266** parameter is usually chosen so that the product of "sz" and "cnt" is less
2267** than 1,000,000.
2268** </ol>
2269** <p>If the "buf" argument is not NULL, then it must
2270** point to a memory buffer with a size that is greater than
2271** or equal to the product of "sz" and "cnt".
2272** The buffer must be aligned to an 8-byte boundary.
2273** The lookaside memory
2274** configuration for a database connection can only be changed when that
2275** connection is not currently using lookaside memory, or in other words
2276** when the value returned by [SQLITE_DBSTATUS_LOOKASIDE_USED] is zero.
2277** Any attempt to change the lookaside memory configuration when lookaside
2278** memory is in use leaves the configuration unchanged and returns
2279** [SQLITE_BUSY].
2280** If the "buf" argument is NULL and an attempt
2281** to allocate memory based on "sz" and "cnt" fails, then
2282** lookaside is silently disabled.
2283** <p>
2284** The [SQLITE_CONFIG_LOOKASIDE] configuration option can be used to set the
2285** default lookaside configuration at initialization. The
2286** [-DSQLITE_DEFAULT_LOOKASIDE] option can be used to set the default lookaside
2287** configuration at compile-time. Typical values for lookaside are 1200 for
2288** "sz" and 40 to 100 for "cnt".
2289** </dd>
2290**
2291** [[SQLITE_DBCONFIG_ENABLE_FKEY]]
2292** <dt>SQLITE_DBCONFIG_ENABLE_FKEY</dt>
2293** <dd> ^This option is used to enable or disable the enforcement of
2294** [foreign key constraints]. This is the same setting that is
2295** enabled or disabled by the [PRAGMA foreign_keys] statement.
2296** The first argument is an integer which is 0 to disable FK enforcement,
2297** positive to enable FK enforcement or negative to leave FK enforcement
2298** unchanged. The second parameter is a pointer to an integer into which
2299** is written 0 or 1 to indicate whether FK enforcement is off or on
2300** following this call. The second parameter may be a NULL pointer, in
2301** which case the FK enforcement setting is not reported back. </dd>
2302**
2303** [[SQLITE_DBCONFIG_ENABLE_TRIGGER]]
2304** <dt>SQLITE_DBCONFIG_ENABLE_TRIGGER</dt>
2305** <dd> ^This option is used to enable or disable [CREATE TRIGGER | triggers].
2306** There should be two additional arguments.
2307** The first argument is an integer which is 0 to disable triggers,
2308** positive to enable triggers or negative to leave the setting unchanged.
2309** The second parameter is a pointer to an integer into which
2310** is written 0 or 1 to indicate whether triggers are disabled or enabled
2311** following this call. The second parameter may be a NULL pointer, in
2312** which case the trigger setting is not reported back.
2313**
2314** <p>Originally this option disabled all triggers. ^(However, since
2315** SQLite version 3.35.0, TEMP triggers are still allowed even if
2316** this option is off. So, in other words, this option now only disables
2317** triggers in the main database schema or in the schemas of [ATTACH]-ed
2318** databases.)^ </dd>
2319**
2320** [[SQLITE_DBCONFIG_ENABLE_VIEW]]
2321** <dt>SQLITE_DBCONFIG_ENABLE_VIEW</dt>
2322** <dd> ^This option is used to enable or disable [CREATE VIEW | views].
2323** There must be two additional arguments.
2324** The first argument is an integer which is 0 to disable views,
2325** positive to enable views or negative to leave the setting unchanged.
2326** The second parameter is a pointer to an integer into which
2327** is written 0 or 1 to indicate whether views are disabled or enabled
2328** following this call. The second parameter may be a NULL pointer, in
2329** which case the view setting is not reported back.
2330**
2331** <p>Originally this option disabled all views. ^(However, since
2332** SQLite version 3.35.0, TEMP views are still allowed even if
2333** this option is off. So, in other words, this option now only disables
2334** views in the main database schema or in the schemas of ATTACH-ed
2335** databases.)^ </dd>
2336**
2337** [[SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER]]
2338** <dt>SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER</dt>
2339** <dd> ^This option is used to enable or disable the
2340** [fts3_tokenizer()] function which is part of the
2341** [FTS3] full-text search engine extension.
2342** There must be two additional arguments.
2343** The first argument is an integer which is 0 to disable fts3_tokenizer() or
2344** positive to enable fts3_tokenizer() or negative to leave the setting
2345** unchanged.
2346** The second parameter is a pointer to an integer into which
2347** is written 0 or 1 to indicate whether fts3_tokenizer is disabled or enabled
2348** following this call. The second parameter may be a NULL pointer, in
2349** which case the new setting is not reported back. </dd>
2350**
2351** [[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION]]
2352** <dt>SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION</dt>
2353** <dd> ^This option is used to enable or disable the [sqlite3_load_extension()]
2354** interface independently of the [load_extension()] SQL function.
2355** The [sqlite3_enable_load_extension()] API enables or disables both the
2356** C-API [sqlite3_load_extension()] and the SQL function [load_extension()].
2357** There must be two additional arguments.
2358** When the first argument to this interface is 1, then only the C-API is
2359** enabled and the SQL function remains disabled. If the first argument to
2360** this interface is 0, then both the C-API and the SQL function are disabled.
2361** If the first argument is -1, then no changes are made to state of either the
2362** C-API or the SQL function.
2363** The second parameter is a pointer to an integer into which
2364** is written 0 or 1 to indicate whether [sqlite3_load_extension()] interface
2365** is disabled or enabled following this call. The second parameter may
2366** be a NULL pointer, in which case the new setting is not reported back.
2367** </dd>
2368**
2369** [[SQLITE_DBCONFIG_MAINDBNAME]] <dt>SQLITE_DBCONFIG_MAINDBNAME</dt>
2370** <dd> ^This option is used to change the name of the "main" database
2371** schema. This option does not follow the
2372** [DBCONFIG arguments|usual SQLITE_DBCONFIG argument format].
2373** This option takes exactly one additional argument so that the
2374** [sqlite3_db_config()] call has a total of three parameters. The
2375** extra argument must be a pointer to a constant UTF8 string which
2376** will become the new schema name in place of "main". ^SQLite does
2377** not make a copy of the new main schema name string, so the application
2378** must ensure that the argument passed into SQLITE_DBCONFIG MAINDBNAME
2379** is unchanged until after the database connection closes.
2380** </dd>
2381**
2382** [[SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE]]
2383** <dt>SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE</dt>
2384** <dd> Usually, when a database in [WAL mode] is closed or detached from a
2385** database handle, SQLite checks if if there are other connections to the
2386** same database, and if there are no other database connection (if the
2387** connection being closed is the last open connection to the database),
2388** then SQLite performs a [checkpoint] before closing the connection and
2389** deletes the WAL file. The SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE option can
2390** be used to override that behavior. The first argument passed to this
2391** operation (the third parameter to [sqlite3_db_config()]) is an integer
2392** which is positive to disable checkpoints-on-close, or zero (the default)
2393** to enable them, and negative to leave the setting unchanged.
2394** The second argument (the fourth parameter) is a pointer to an integer
2395** into which is written 0 or 1 to indicate whether checkpoints-on-close
2396** have been disabled - 0 if they are not disabled, 1 if they are.
2397** </dd>
2398**
2399** [[SQLITE_DBCONFIG_ENABLE_QPSG]] <dt>SQLITE_DBCONFIG_ENABLE_QPSG</dt>
2400** <dd>^(The SQLITE_DBCONFIG_ENABLE_QPSG option activates or deactivates
2401** the [query planner stability guarantee] (QPSG). When the QPSG is active,
2402** a single SQL query statement will always use the same algorithm regardless
2403** of values of [bound parameters].)^ The QPSG disables some query optimizations
2404** that look at the values of bound parameters, which can make some queries
2405** slower. But the QPSG has the advantage of more predictable behavior. With
2406** the QPSG active, SQLite will always use the same query plan in the field as
2407** was used during testing in the lab.
2408** The first argument to this setting is an integer which is 0 to disable
2409** the QPSG, positive to enable QPSG, or negative to leave the setting
2410** unchanged. The second parameter is a pointer to an integer into which
2411** is written 0 or 1 to indicate whether the QPSG is disabled or enabled
2412** following this call.
2413** </dd>
2414**
2415** [[SQLITE_DBCONFIG_TRIGGER_EQP]] <dt>SQLITE_DBCONFIG_TRIGGER_EQP</dt>
2416** <dd> By default, the output of EXPLAIN QUERY PLAN commands does not
2417** include output for any operations performed by trigger programs. This
2418** option is used to set or clear (the default) a flag that governs this
2419** behavior. The first parameter passed to this operation is an integer -
2420** positive to enable output for trigger programs, or zero to disable it,
2421** or negative to leave the setting unchanged.
2422** The second parameter is a pointer to an integer into which is written
2423** 0 or 1 to indicate whether output-for-triggers has been disabled - 0 if
2424** it is not disabled, 1 if it is.
2425** </dd>
2426**
2427** [[SQLITE_DBCONFIG_RESET_DATABASE]] <dt>SQLITE_DBCONFIG_RESET_DATABASE</dt>
2428** <dd> Set the SQLITE_DBCONFIG_RESET_DATABASE flag and then run
2429** [VACUUM] in order to reset a database back to an empty database
2430** with no schema and no content. The following process works even for
2431** a badly corrupted database file:
2432** <ol>
2433** <li> If the database connection is newly opened, make sure it has read the
2434** database schema by preparing then discarding some query against the
2435** database, or calling sqlite3_table_column_metadata(), ignoring any
2436** errors. This step is only necessary if the application desires to keep
2437** the database in WAL mode after the reset if it was in WAL mode before
2438** the reset.
2439** <li> sqlite3_db_config(db, SQLITE_DBCONFIG_RESET_DATABASE, 1, 0);
2440** <li> [sqlite3_exec](db, "[VACUUM]", 0, 0, 0);
2441** <li> sqlite3_db_config(db, SQLITE_DBCONFIG_RESET_DATABASE, 0, 0);
2442** </ol>
2443** Because resetting a database is destructive and irreversible, the
2444** process requires the use of this obscure API and multiple steps to
2445** help ensure that it does not happen by accident. Because this
2446** feature must be capable of resetting corrupt databases, and
2447** shutting down virtual tables may require access to that corrupt
2448** storage, the library must abandon any installed virtual tables
2449** without calling their xDestroy() methods.
2450**
2451** [[SQLITE_DBCONFIG_DEFENSIVE]] <dt>SQLITE_DBCONFIG_DEFENSIVE</dt>
2452** <dd>The SQLITE_DBCONFIG_DEFENSIVE option activates or deactivates the
2453** "defensive" flag for a database connection. When the defensive
2454** flag is enabled, language features that allow ordinary SQL to
2455** deliberately corrupt the database file are disabled. The disabled
2456** features include but are not limited to the following:
2457** <ul>
2458** <li> The [PRAGMA writable_schema=ON] statement.
2459** <li> The [PRAGMA journal_mode=OFF] statement.
2460** <li> The [PRAGMA schema_version=N] statement.
2461** <li> Writes to the [sqlite_dbpage] virtual table.
2462** <li> Direct writes to [shadow tables].
2463** </ul>
2464** </dd>
2465**
2466** [[SQLITE_DBCONFIG_WRITABLE_SCHEMA]] <dt>SQLITE_DBCONFIG_WRITABLE_SCHEMA</dt>
2467** <dd>The SQLITE_DBCONFIG_WRITABLE_SCHEMA option activates or deactivates the
2468** "writable_schema" flag. This has the same effect and is logically equivalent
2469** to setting [PRAGMA writable_schema=ON] or [PRAGMA writable_schema=OFF].
2470** The first argument to this setting is an integer which is 0 to disable
2471** the writable_schema, positive to enable writable_schema, or negative to
2472** leave the setting unchanged. The second parameter is a pointer to an
2473** integer into which is written 0 or 1 to indicate whether the writable_schema
2474** is enabled or disabled following this call.
2475** </dd>
2476**
2477** [[SQLITE_DBCONFIG_LEGACY_ALTER_TABLE]]
2478** <dt>SQLITE_DBCONFIG_LEGACY_ALTER_TABLE</dt>
2479** <dd>The SQLITE_DBCONFIG_LEGACY_ALTER_TABLE option activates or deactivates
2480** the legacy behavior of the [ALTER TABLE RENAME] command such it
2481** behaves as it did prior to [version 3.24.0] (2018-06-04). See the
2482** "Compatibility Notice" on the [ALTER TABLE RENAME documentation] for
2483** additional information. This feature can also be turned on and off
2484** using the [PRAGMA legacy_alter_table] statement.
2485** </dd>
2486**
2487** [[SQLITE_DBCONFIG_DQS_DML]]
2488** <dt>SQLITE_DBCONFIG_DQS_DML</dt>
2489** <dd>The SQLITE_DBCONFIG_DQS_DML option activates or deactivates
2490** the legacy [double-quoted string literal] misfeature for DML statements
2491** only, that is DELETE, INSERT, SELECT, and UPDATE statements. The
2492** default value of this setting is determined by the [-DSQLITE_DQS]
2493** compile-time option.
2494** </dd>
2495**
2496** [[SQLITE_DBCONFIG_DQS_DDL]]
2497** <dt>SQLITE_DBCONFIG_DQS_DDL</dt>
2498** <dd>The SQLITE_DBCONFIG_DQS option activates or deactivates
2499** the legacy [double-quoted string literal] misfeature for DDL statements,
2500** such as CREATE TABLE and CREATE INDEX. The
2501** default value of this setting is determined by the [-DSQLITE_DQS]
2502** compile-time option.
2503** </dd>
2504**
2505** [[SQLITE_DBCONFIG_TRUSTED_SCHEMA]]
2506** <dt>SQLITE_DBCONFIG_TRUSTED_SCHEMA</dt>
2507** <dd>The SQLITE_DBCONFIG_TRUSTED_SCHEMA option tells SQLite to
2508** assume that database schemas are untainted by malicious content.
2509** When the SQLITE_DBCONFIG_TRUSTED_SCHEMA option is disabled, SQLite
2510** takes additional defensive steps to protect the application from harm
2511** including:
2512** <ul>
2513** <li> Prohibit the use of SQL functions inside triggers, views,
2514** CHECK constraints, DEFAULT clauses, expression indexes,
2515** partial indexes, or generated columns
2516** unless those functions are tagged with [SQLITE_INNOCUOUS].
2517** <li> Prohibit the use of virtual tables inside of triggers or views
2518** unless those virtual tables are tagged with [SQLITE_VTAB_INNOCUOUS].
2519** </ul>
2520** This setting defaults to "on" for legacy compatibility, however
2521** all applications are advised to turn it off if possible. This setting
2522** can also be controlled using the [PRAGMA trusted_schema] statement.
2523** </dd>
2524**
2525** [[SQLITE_DBCONFIG_LEGACY_FILE_FORMAT]]
2526** <dt>SQLITE_DBCONFIG_LEGACY_FILE_FORMAT</dt>
2527** <dd>The SQLITE_DBCONFIG_LEGACY_FILE_FORMAT option activates or deactivates
2528** the legacy file format flag. When activated, this flag causes all newly
2529** created database file to have a schema format version number (the 4-byte
2530** integer found at offset 44 into the database header) of 1. This in turn
2531** means that the resulting database file will be readable and writable by
2532** any SQLite version back to 3.0.0 ([dateof:3.0.0]). Without this setting,
2533** newly created databases are generally not understandable by SQLite versions
2534** prior to 3.3.0 ([dateof:3.3.0]). As these words are written, there
2535** is now scarcely any need to generate database files that are compatible
2536** all the way back to version 3.0.0, and so this setting is of little
2537** practical use, but is provided so that SQLite can continue to claim the
2538** ability to generate new database files that are compatible with version
2539** 3.0.0.
2540** <p>Note that when the SQLITE_DBCONFIG_LEGACY_FILE_FORMAT setting is on,
2541** the [VACUUM] command will fail with an obscure error when attempting to
2542** process a table with generated columns and a descending index. This is
2543** not considered a bug since SQLite versions 3.3.0 and earlier do not support
2544** either generated columns or descending indexes.
2545** </dd>
2546**
2547** [[SQLITE_DBCONFIG_STMT_SCANSTATUS]]
2548** <dt>SQLITE_DBCONFIG_STMT_SCANSTATUS</dt>
2549** <dd>The SQLITE_DBCONFIG_STMT_SCANSTATUS option is only useful in
2550** SQLITE_ENABLE_STMT_SCANSTATUS builds. In this case, it sets or clears
2551** a flag that enables collection of the sqlite3_stmt_scanstatus_v2()
2552** statistics. For statistics to be collected, the flag must be set on
2553** the database handle both when the SQL statement is prepared and when it
2554** is stepped. The flag is set (collection of statistics is enabled)
2555** by default. <p>This option takes two arguments: an integer and a pointer to
2556** an integer.. The first argument is 1, 0, or -1 to enable, disable, or
2557** leave unchanged the statement scanstatus option. If the second argument
2558** is not NULL, then the value of the statement scanstatus setting after
2559** processing the first argument is written into the integer that the second
2560** argument points to.
2561** </dd>
2562**
2563** [[SQLITE_DBCONFIG_REVERSE_SCANORDER]]
2564** <dt>SQLITE_DBCONFIG_REVERSE_SCANORDER</dt>
2565** <dd>The SQLITE_DBCONFIG_REVERSE_SCANORDER option changes the default order
2566** in which tables and indexes are scanned so that the scans start at the end
2567** and work toward the beginning rather than starting at the beginning and
2568** working toward the end. Setting SQLITE_DBCONFIG_REVERSE_SCANORDER is the
2569** same as setting [PRAGMA reverse_unordered_selects]. <p>This option takes
2570** two arguments which are an integer and a pointer to an integer. The first
2571** argument is 1, 0, or -1 to enable, disable, or leave unchanged the
2572** reverse scan order flag, respectively. If the second argument is not NULL,
2573** then 0 or 1 is written into the integer that the second argument points to
2574** depending on if the reverse scan order flag is set after processing the
2575** first argument.
2576** </dd>
2577**
2578** [[SQLITE_DBCONFIG_ENABLE_ATTACH_CREATE]]
2579** <dt>SQLITE_DBCONFIG_ENABLE_ATTACH_CREATE</dt>
2580** <dd>The SQLITE_DBCONFIG_ENABLE_ATTACH_CREATE option enables or disables
2581** the ability of the [ATTACH DATABASE] SQL command to create a new database
2582** file if the database filed named in the ATTACH command does not already
2583** exist. This ability of ATTACH to create a new database is enabled by
2584** default. Applications can disable or reenable the ability for ATTACH to
2585** create new database files using this DBCONFIG option.<p>
2586** This option takes two arguments which are an integer and a pointer
2587** to an integer. The first argument is 1, 0, or -1 to enable, disable, or
2588** leave unchanged the attach-create flag, respectively. If the second
2589** argument is not NULL, then 0 or 1 is written into the integer that the
2590** second argument points to depending on if the attach-create flag is set
2591** after processing the first argument.
2592** </dd>
2593**
2594** [[SQLITE_DBCONFIG_ENABLE_ATTACH_WRITE]]
2595** <dt>SQLITE_DBCONFIG_ENABLE_ATTACH_WRITE</dt>
2596** <dd>The SQLITE_DBCONFIG_ENABLE_ATTACH_WRITE option enables or disables the
2597** ability of the [ATTACH DATABASE] SQL command to open a database for writing.
2598** This capability is enabled by default. Applications can disable or
2599** reenable this capability using the current DBCONFIG option. If the
2600** the this capability is disabled, the [ATTACH] command will still work,
2601** but the database will be opened read-only. If this option is disabled,
2602** then the ability to create a new database using [ATTACH] is also disabled,
2603** regardless of the value of the [SQLITE_DBCONFIG_ENABLE_ATTACH_CREATE]
2604** option.<p>
2605** This option takes two arguments which are an integer and a pointer
2606** to an integer. The first argument is 1, 0, or -1 to enable, disable, or
2607** leave unchanged the ability to ATTACH another database for writing,
2608** respectively. If the second argument is not NULL, then 0 or 1 is written
2609** into the integer to which the second argument points, depending on whether
2610** the ability to ATTACH a read/write database is enabled or disabled
2611** after processing the first argument.
2612** </dd>
2613**
2614** [[SQLITE_DBCONFIG_ENABLE_COMMENTS]]
2615** <dt>SQLITE_DBCONFIG_ENABLE_COMMENTS</dt>
2616** <dd>The SQLITE_DBCONFIG_ENABLE_COMMENTS option enables or disables the
2617** ability to include comments in SQL text. Comments are enabled by default.
2618** An application can disable or reenable comments in SQL text using this
2619** DBCONFIG option.<p>
2620** This option takes two arguments which are an integer and a pointer
2621** to an integer. The first argument is 1, 0, or -1 to enable, disable, or
2622** leave unchanged the ability to use comments in SQL text,
2623** respectively. If the second argument is not NULL, then 0 or 1 is written
2624** into the integer that the second argument points to depending on if
2625** comments are allowed in SQL text after processing the first argument.
2626** </dd>
2627**
2628** </dl>
2629**
2630** [[DBCONFIG arguments]] <h3>Arguments To SQLITE_DBCONFIG Options</h3>
2631**
2632** <p>Most of the SQLITE_DBCONFIG options take two arguments, so that the
2633** overall call to [sqlite3_db_config()] has a total of four parameters.
2634** The first argument (the third parameter to sqlite3_db_config()) is a integer.
2635** The second argument is a pointer to an integer. If the first argument is 1,
2636** then the option becomes enabled. If the first integer argument is 0, then the
2637** option is disabled. If the first argument is -1, then the option setting
2638** is unchanged. The second argument, the pointer to an integer, may be NULL.
2639** If the second argument is not NULL, then a value of 0 or 1 is written into
2640** the integer to which the second argument points, depending on whether the
2641** setting is disabled or enabled after applying any changes specified by
2642** the first argument.
2643**
2644** <p>While most SQLITE_DBCONFIG options use the argument format
2645** described in the previous paragraph, the [SQLITE_DBCONFIG_MAINDBNAME]
2646** and [SQLITE_DBCONFIG_LOOKASIDE] options are different. See the
2647** documentation of those exceptional options for details.
2648*/
2649#define SQLITE_DBCONFIG_MAINDBNAME 1000 /* const char* */
2650#define SQLITE_DBCONFIG_LOOKASIDE 1001 /* void* int int */
2651#define SQLITE_DBCONFIG_ENABLE_FKEY 1002 /* int int* */
2652#define SQLITE_DBCONFIG_ENABLE_TRIGGER 1003 /* int int* */
2653#define SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER 1004 /* int int* */
2654#define SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION 1005 /* int int* */
2655#define SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE 1006 /* int int* */
2656#define SQLITE_DBCONFIG_ENABLE_QPSG 1007 /* int int* */
2657#define SQLITE_DBCONFIG_TRIGGER_EQP 1008 /* int int* */
2658#define SQLITE_DBCONFIG_RESET_DATABASE 1009 /* int int* */
2659#define SQLITE_DBCONFIG_DEFENSIVE 1010 /* int int* */
2660#define SQLITE_DBCONFIG_WRITABLE_SCHEMA 1011 /* int int* */
2661#define SQLITE_DBCONFIG_LEGACY_ALTER_TABLE 1012 /* int int* */
2662#define SQLITE_DBCONFIG_DQS_DML 1013 /* int int* */
2663#define SQLITE_DBCONFIG_DQS_DDL 1014 /* int int* */
2664#define SQLITE_DBCONFIG_ENABLE_VIEW 1015 /* int int* */
2665#define SQLITE_DBCONFIG_LEGACY_FILE_FORMAT 1016 /* int int* */
2666#define SQLITE_DBCONFIG_TRUSTED_SCHEMA 1017 /* int int* */
2667#define SQLITE_DBCONFIG_STMT_SCANSTATUS 1018 /* int int* */
2668#define SQLITE_DBCONFIG_REVERSE_SCANORDER 1019 /* int int* */
2669#define SQLITE_DBCONFIG_ENABLE_ATTACH_CREATE 1020 /* int int* */
2670#define SQLITE_DBCONFIG_ENABLE_ATTACH_WRITE 1021 /* int int* */
2671#define SQLITE_DBCONFIG_ENABLE_COMMENTS 1022 /* int int* */
2672#define SQLITE_DBCONFIG_MAX 1022 /* Largest DBCONFIG */
2673
2674/*
2675** CAPI3REF: Enable Or Disable Extended Result Codes
2676** METHOD: sqlite3
2677**
2678** ^The sqlite3_extended_result_codes() routine enables or disables the
2679** [extended result codes] feature of SQLite. ^The extended result
2680** codes are disabled by default for historical compatibility.
2681*/
2682SQLITE_API int sqlite3_extended_result_codes(sqlite3*, int onoff);
2683
2684/*
2685** CAPI3REF: Last Insert Rowid
2686** METHOD: sqlite3
2687**
2688** ^Each entry in most SQLite tables (except for [WITHOUT ROWID] tables)
2689** has a unique 64-bit signed
2690** integer key called the [ROWID | "rowid"]. ^The rowid is always available
2691** as an undeclared column named ROWID, OID, or _ROWID_ as long as those
2692** names are not also used by explicitly declared columns. ^If
2693** the table has a column of type [INTEGER PRIMARY KEY] then that column
2694** is another alias for the rowid.
2695**
2696** ^The sqlite3_last_insert_rowid(D) interface usually returns the [rowid] of
2697** the most recent successful [INSERT] into a rowid table or [virtual table]
2698** on database connection D. ^Inserts into [WITHOUT ROWID] tables are not
2699** recorded. ^If no successful [INSERT]s into rowid tables have ever occurred
2700** on the database connection D, then sqlite3_last_insert_rowid(D) returns
2701** zero.
2702**
2703** As well as being set automatically as rows are inserted into database
2704** tables, the value returned by this function may be set explicitly by
2705** [sqlite3_set_last_insert_rowid()]
2706**
2707** Some virtual table implementations may INSERT rows into rowid tables as
2708** part of committing a transaction (e.g. to flush data accumulated in memory
2709** to disk). In this case subsequent calls to this function return the rowid
2710** associated with these internal INSERT operations, which leads to
2711** unintuitive results. Virtual table implementations that do write to rowid
2712** tables in this way can avoid this problem by restoring the original
2713** rowid value using [sqlite3_set_last_insert_rowid()] before returning
2714** control to the user.
2715**
2716** ^(If an [INSERT] occurs within a trigger then this routine will
2717** return the [rowid] of the inserted row as long as the trigger is
2718** running. Once the trigger program ends, the value returned
2719** by this routine reverts to what it was before the trigger was fired.)^
2720**
2721** ^An [INSERT] that fails due to a constraint violation is not a
2722** successful [INSERT] and does not change the value returned by this
2723** routine. ^Thus INSERT OR FAIL, INSERT OR IGNORE, INSERT OR ROLLBACK,
2724** and INSERT OR ABORT make no changes to the return value of this
2725** routine when their insertion fails. ^(When INSERT OR REPLACE
2726** encounters a constraint violation, it does not fail. The
2727** INSERT continues to completion after deleting rows that caused
2728** the constraint problem so INSERT OR REPLACE will always change
2729** the return value of this interface.)^
2730**
2731** ^For the purposes of this routine, an [INSERT] is considered to
2732** be successful even if it is subsequently rolled back.
2733**
2734** This function is accessible to SQL statements via the
2735** [last_insert_rowid() SQL function].
2736**
2737** If a separate thread performs a new [INSERT] on the same
2738** database connection while the [sqlite3_last_insert_rowid()]
2739** function is running and thus changes the last insert [rowid],
2740** then the value returned by [sqlite3_last_insert_rowid()] is
2741** unpredictable and might not equal either the old or the new
2742** last insert [rowid].
2743*/
2744SQLITE_API sqlite3_int64 sqlite3_last_insert_rowid(sqlite3*);
2745
2746/*
2747** CAPI3REF: Set the Last Insert Rowid value.
2748** METHOD: sqlite3
2749**
2750** The sqlite3_set_last_insert_rowid(D, R) method allows the application to
2751** set the value returned by calling sqlite3_last_insert_rowid(D) to R
2752** without inserting a row into the database.
2753*/
2754SQLITE_API void sqlite3_set_last_insert_rowid(sqlite3*,sqlite3_int64);
2755
2756/*
2757** CAPI3REF: Count The Number Of Rows Modified
2758** METHOD: sqlite3
2759**
2760** ^These functions return the number of rows modified, inserted or
2761** deleted by the most recently completed INSERT, UPDATE or DELETE
2762** statement on the database connection specified by the only parameter.
2763** The two functions are identical except for the type of the return value
2764** and that if the number of rows modified by the most recent INSERT, UPDATE,
2765** or DELETE is greater than the maximum value supported by type "int", then
2766** the return value of sqlite3_changes() is undefined. ^Executing any other
2767** type of SQL statement does not modify the value returned by these functions.
2768** For the purposes of this interface, a CREATE TABLE AS SELECT statement
2769** does not count as an INSERT, UPDATE or DELETE statement and hence the rows
2770** added to the new table by the CREATE TABLE AS SELECT statement are not
2771** counted.
2772**
2773** ^Only changes made directly by the INSERT, UPDATE or DELETE statement are
2774** considered - auxiliary changes caused by [CREATE TRIGGER | triggers],
2775** [foreign key actions] or [REPLACE] constraint resolution are not counted.
2776**
2777** Changes to a view that are intercepted by
2778** [INSTEAD OF trigger | INSTEAD OF triggers] are not counted. ^The value
2779** returned by sqlite3_changes() immediately after an INSERT, UPDATE or
2780** DELETE statement run on a view is always zero. Only changes made to real
2781** tables are counted.
2782**
2783** Things are more complicated if the sqlite3_changes() function is
2784** executed while a trigger program is running. This may happen if the
2785** program uses the [changes() SQL function], or if some other callback
2786** function invokes sqlite3_changes() directly. Essentially:
2787**
2788** <ul>
2789** <li> ^(Before entering a trigger program the value returned by
2790** sqlite3_changes() function is saved. After the trigger program
2791** has finished, the original value is restored.)^
2792**
2793** <li> ^(Within a trigger program each INSERT, UPDATE and DELETE
2794** statement sets the value returned by sqlite3_changes()
2795** upon completion as normal. Of course, this value will not include
2796** any changes performed by sub-triggers, as the sqlite3_changes()
2797** value will be saved and restored after each sub-trigger has run.)^
2798** </ul>
2799**
2800** ^This means that if the changes() SQL function (or similar) is used
2801** by the first INSERT, UPDATE or DELETE statement within a trigger, it
2802** returns the value as set when the calling statement began executing.
2803** ^If it is used by the second or subsequent such statement within a trigger
2804** program, the value returned reflects the number of rows modified by the
2805** previous INSERT, UPDATE or DELETE statement within the same trigger.
2806**
2807** If a separate thread makes changes on the same database connection
2808** while [sqlite3_changes()] is running then the value returned
2809** is unpredictable and not meaningful.
2810**
2811** See also:
2812** <ul>
2813** <li> the [sqlite3_total_changes()] interface
2814** <li> the [count_changes pragma]
2815** <li> the [changes() SQL function]
2816** <li> the [data_version pragma]
2817** </ul>
2818*/
2819SQLITE_API int sqlite3_changes(sqlite3*);
2820SQLITE_API sqlite3_int64 sqlite3_changes64(sqlite3*);
2821
2822/*
2823** CAPI3REF: Total Number Of Rows Modified
2824** METHOD: sqlite3
2825**
2826** ^These functions return the total number of rows inserted, modified or
2827** deleted by all [INSERT], [UPDATE] or [DELETE] statements completed
2828** since the database connection was opened, including those executed as
2829** part of trigger programs. The two functions are identical except for the
2830** type of the return value and that if the number of rows modified by the
2831** connection exceeds the maximum value supported by type "int", then
2832** the return value of sqlite3_total_changes() is undefined. ^Executing
2833** any other type of SQL statement does not affect the value returned by
2834** sqlite3_total_changes().
2835**
2836** ^Changes made as part of [foreign key actions] are included in the
2837** count, but those made as part of REPLACE constraint resolution are
2838** not. ^Changes to a view that are intercepted by INSTEAD OF triggers
2839** are not counted.
2840**
2841** The [sqlite3_total_changes(D)] interface only reports the number
2842** of rows that changed due to SQL statement run against database
2843** connection D. Any changes by other database connections are ignored.
2844** To detect changes against a database file from other database
2845** connections use the [PRAGMA data_version] command or the
2846** [SQLITE_FCNTL_DATA_VERSION] [file control].
2847**
2848** If a separate thread makes changes on the same database connection
2849** while [sqlite3_total_changes()] is running then the value
2850** returned is unpredictable and not meaningful.
2851**
2852** See also:
2853** <ul>
2854** <li> the [sqlite3_changes()] interface
2855** <li> the [count_changes pragma]
2856** <li> the [changes() SQL function]
2857** <li> the [data_version pragma]
2858** <li> the [SQLITE_FCNTL_DATA_VERSION] [file control]
2859** </ul>
2860*/
2861SQLITE_API int sqlite3_total_changes(sqlite3*);
2862SQLITE_API sqlite3_int64 sqlite3_total_changes64(sqlite3*);
2863
2864/*
2865** CAPI3REF: Interrupt A Long-Running Query
2866** METHOD: sqlite3
2867**
2868** ^This function causes any pending database operation to abort and
2869** return at its earliest opportunity. This routine is typically
2870** called in response to a user action such as pressing "Cancel"
2871** or Ctrl-C where the user wants a long query operation to halt
2872** immediately.
2873**
2874** ^It is safe to call this routine from a thread different from the
2875** thread that is currently running the database operation. But it
2876** is not safe to call this routine with a [database connection] that
2877** is closed or might close before sqlite3_interrupt() returns.
2878**
2879** ^If an SQL operation is very nearly finished at the time when
2880** sqlite3_interrupt() is called, then it might not have an opportunity
2881** to be interrupted and might continue to completion.
2882**
2883** ^An SQL operation that is interrupted will return [SQLITE_INTERRUPT].
2884** ^If the interrupted SQL operation is an INSERT, UPDATE, or DELETE
2885** that is inside an explicit transaction, then the entire transaction
2886** will be rolled back automatically.
2887**
2888** ^The sqlite3_interrupt(D) call is in effect until all currently running
2889** SQL statements on [database connection] D complete. ^Any new SQL statements
2890** that are started after the sqlite3_interrupt() call and before the
2891** running statement count reaches zero are interrupted as if they had been
2892** running prior to the sqlite3_interrupt() call. ^New SQL statements
2893** that are started after the running statement count reaches zero are
2894** not effected by the sqlite3_interrupt().
2895** ^A call to sqlite3_interrupt(D) that occurs when there are no running
2896** SQL statements is a no-op and has no effect on SQL statements
2897** that are started after the sqlite3_interrupt() call returns.
2898**
2899** ^The [sqlite3_is_interrupted(D)] interface can be used to determine whether
2900** or not an interrupt is currently in effect for [database connection] D.
2901** It returns 1 if an interrupt is currently in effect, or 0 otherwise.
2902*/
2903SQLITE_API void sqlite3_interrupt(sqlite3*);
2904SQLITE_API int sqlite3_is_interrupted(sqlite3*);
2905
2906/*
2907** CAPI3REF: Determine If An SQL Statement Is Complete
2908**
2909** These routines are useful during command-line input to determine if the
2910** currently entered text seems to form a complete SQL statement or
2911** if additional input is needed before sending the text into
2912** SQLite for parsing. ^These routines return 1 if the input string
2913** appears to be a complete SQL statement. ^A statement is judged to be
2914** complete if it ends with a semicolon token and is not a prefix of a
2915** well-formed CREATE TRIGGER statement. ^Semicolons that are embedded within
2916** string literals or quoted identifier names or comments are not
2917** independent tokens (they are part of the token in which they are
2918** embedded) and thus do not count as a statement terminator. ^Whitespace
2919** and comments that follow the final semicolon are ignored.
2920**
2921** ^These routines return 0 if the statement is incomplete. ^If a
2922** memory allocation fails, then SQLITE_NOMEM is returned.
2923**
2924** ^These routines do not parse the SQL statements thus
2925** will not detect syntactically incorrect SQL.
2926**
2927** ^(If SQLite has not been initialized using [sqlite3_initialize()] prior
2928** to invoking sqlite3_complete16() then sqlite3_initialize() is invoked
2929** automatically by sqlite3_complete16(). If that initialization fails,
2930** then the return value from sqlite3_complete16() will be non-zero
2931** regardless of whether or not the input SQL is complete.)^
2932**
2933** The input to [sqlite3_complete()] must be a zero-terminated
2934** UTF-8 string.
2935**
2936** The input to [sqlite3_complete16()] must be a zero-terminated
2937** UTF-16 string in native byte order.
2938*/
2939SQLITE_API int sqlite3_complete(const char *sql);
2940SQLITE_API int sqlite3_complete16(const void *sql);
2941
2942/*
2943** CAPI3REF: Register A Callback To Handle SQLITE_BUSY Errors
2944** KEYWORDS: {busy-handler callback} {busy handler}
2945** METHOD: sqlite3
2946**
2947** ^The sqlite3_busy_handler(D,X,P) routine sets a callback function X
2948** that might be invoked with argument P whenever
2949** an attempt is made to access a database table associated with
2950** [database connection] D when another thread
2951** or process has the table locked.
2952** The sqlite3_busy_handler() interface is used to implement
2953** [sqlite3_busy_timeout()] and [PRAGMA busy_timeout].
2954**
2955** ^If the busy callback is NULL, then [SQLITE_BUSY]
2956** is returned immediately upon encountering the lock. ^If the busy callback
2957** is not NULL, then the callback might be invoked with two arguments.
2958**
2959** ^The first argument to the busy handler is a copy of the void* pointer which
2960** is the third argument to sqlite3_busy_handler(). ^The second argument to
2961** the busy handler callback is the number of times that the busy handler has
2962** been invoked previously for the same locking event. ^If the
2963** busy callback returns 0, then no additional attempts are made to
2964** access the database and [SQLITE_BUSY] is returned
2965** to the application.
2966** ^If the callback returns non-zero, then another attempt
2967** is made to access the database and the cycle repeats.
2968**
2969** The presence of a busy handler does not guarantee that it will be invoked
2970** when there is lock contention. ^If SQLite determines that invoking the busy
2971** handler could result in a deadlock, it will go ahead and return [SQLITE_BUSY]
2972** to the application instead of invoking the
2973** busy handler.
2974** Consider a scenario where one process is holding a read lock that
2975** it is trying to promote to a reserved lock and
2976** a second process is holding a reserved lock that it is trying
2977** to promote to an exclusive lock. The first process cannot proceed
2978** because it is blocked by the second and the second process cannot
2979** proceed because it is blocked by the first. If both processes
2980** invoke the busy handlers, neither will make any progress. Therefore,
2981** SQLite returns [SQLITE_BUSY] for the first process, hoping that this
2982** will induce the first process to release its read lock and allow
2983** the second process to proceed.
2984**
2985** ^The default busy callback is NULL.
2986**
2987** ^(There can only be a single busy handler defined for each
2988** [database connection]. Setting a new busy handler clears any
2989** previously set handler.)^ ^Note that calling [sqlite3_busy_timeout()]
2990** or evaluating [PRAGMA busy_timeout=N] will change the
2991** busy handler and thus clear any previously set busy handler.
2992**
2993** The busy callback should not take any actions which modify the
2994** database connection that invoked the busy handler. In other words,
2995** the busy handler is not reentrant. Any such actions
2996** result in undefined behavior.
2997**
2998** A busy handler must not close the database connection
2999** or [prepared statement] that invoked the busy handler.
3000*/
3001SQLITE_API int sqlite3_busy_handler(sqlite3*,int(*)(void*,int),void*);
3002
3003/*
3004** CAPI3REF: Set A Busy Timeout
3005** METHOD: sqlite3
3006**
3007** ^This routine sets a [sqlite3_busy_handler | busy handler] that sleeps
3008** for a specified amount of time when a table is locked. ^The handler
3009** will sleep multiple times until at least "ms" milliseconds of sleeping
3010** have accumulated. ^After at least "ms" milliseconds of sleeping,
3011** the handler returns 0 which causes [sqlite3_step()] to return
3012** [SQLITE_BUSY].
3013**
3014** ^Calling this routine with an argument less than or equal to zero
3015** turns off all busy handlers.
3016**
3017** ^(There can only be a single busy handler for a particular
3018** [database connection] at any given moment. If another busy handler
3019** was defined (using [sqlite3_busy_handler()]) prior to calling
3020** this routine, that other busy handler is cleared.)^
3021**
3022** See also: [PRAGMA busy_timeout]
3023*/
3024SQLITE_API int sqlite3_busy_timeout(sqlite3*, int ms);
3025
3026/*
3027** CAPI3REF: Set the Setlk Timeout
3028** METHOD: sqlite3
3029**
3030** This routine is only useful in SQLITE_ENABLE_SETLK_TIMEOUT builds. If
3031** the VFS supports blocking locks, it sets the timeout in ms used by
3032** eligible locks taken on wal mode databases by the specified database
3033** handle. In non-SQLITE_ENABLE_SETLK_TIMEOUT builds, or if the VFS does
3034** not support blocking locks, this function is a no-op.
3035**
3036** Passing 0 to this function disables blocking locks altogether. Passing
3037** -1 to this function requests that the VFS blocks for a long time -
3038** indefinitely if possible. The results of passing any other negative value
3039** are undefined.
3040**
3041** Internally, each SQLite database handle store two timeout values - the
3042** busy-timeout (used for rollback mode databases, or if the VFS does not
3043** support blocking locks) and the setlk-timeout (used for blocking locks
3044** on wal-mode databases). The sqlite3_busy_timeout() method sets both
3045** values, this function sets only the setlk-timeout value. Therefore,
3046** to configure separate busy-timeout and setlk-timeout values for a single
3047** database handle, call sqlite3_busy_timeout() followed by this function.
3048**
3049** Whenever the number of connections to a wal mode database falls from
3050** 1 to 0, the last connection takes an exclusive lock on the database,
3051** then checkpoints and deletes the wal file. While it is doing this, any
3052** new connection that tries to read from the database fails with an
3053** SQLITE_BUSY error. Or, if the SQLITE_SETLK_BLOCK_ON_CONNECT flag is
3054** passed to this API, the new connection blocks until the exclusive lock
3055** has been released.
3056*/
3057SQLITE_API int sqlite3_setlk_timeout(sqlite3*, int ms, int flags);
3058
3059/*
3060** CAPI3REF: Flags for sqlite3_setlk_timeout()
3061*/
3062#define SQLITE_SETLK_BLOCK_ON_CONNECT 0x01
3063
3064/*
3065** CAPI3REF: Convenience Routines For Running Queries
3066** METHOD: sqlite3
3067**
3068** This is a legacy interface that is preserved for backwards compatibility.
3069** Use of this interface is not recommended.
3070**
3071** Definition: A <b>result table</b> is memory data structure created by the
3072** [sqlite3_get_table()] interface. A result table records the
3073** complete query results from one or more queries.
3074**
3075** The table conceptually has a number of rows and columns. But
3076** these numbers are not part of the result table itself. These
3077** numbers are obtained separately. Let N be the number of rows
3078** and M be the number of columns.
3079**
3080** A result table is an array of pointers to zero-terminated UTF-8 strings.
3081** There are (N+1)*M elements in the array. The first M pointers point
3082** to zero-terminated strings that contain the names of the columns.
3083** The remaining entries all point to query results. NULL values result
3084** in NULL pointers. All other values are in their UTF-8 zero-terminated
3085** string representation as returned by [sqlite3_column_text()].
3086**
3087** A result table might consist of one or more memory allocations.
3088** It is not safe to pass a result table directly to [sqlite3_free()].
3089** A result table should be deallocated using [sqlite3_free_table()].
3090**
3091** ^(As an example of the result table format, suppose a query result
3092** is as follows:
3093**
3094** <blockquote><pre>
3095** Name | Age
3096** -----------------------
3097** Alice | 43
3098** Bob | 28
3099** Cindy | 21
3100** </pre></blockquote>
3101**
3102** There are two columns (M==2) and three rows (N==3). Thus the
3103** result table has 8 entries. Suppose the result table is stored
3104** in an array named azResult. Then azResult holds this content:
3105**
3106** <blockquote><pre>
3107** azResult[0] = "Name";
3108** azResult[1] = "Age";
3109** azResult[2] = "Alice";
3110** azResult[3] = "43";
3111** azResult[4] = "Bob";
3112** azResult[5] = "28";
3113** azResult[6] = "Cindy";
3114** azResult[7] = "21";
3115** </pre></blockquote>)^
3116**
3117** ^The sqlite3_get_table() function evaluates one or more
3118** semicolon-separated SQL statements in the zero-terminated UTF-8
3119** string of its 2nd parameter and returns a result table to the
3120** pointer given in its 3rd parameter.
3121**
3122** After the application has finished with the result from sqlite3_get_table(),
3123** it must pass the result table pointer to sqlite3_free_table() in order to
3124** release the memory that was malloced. Because of the way the
3125** [sqlite3_malloc()] happens within sqlite3_get_table(), the calling
3126** function must not try to call [sqlite3_free()] directly. Only
3127** [sqlite3_free_table()] is able to release the memory properly and safely.
3128**
3129** The sqlite3_get_table() interface is implemented as a wrapper around
3130** [sqlite3_exec()]. The sqlite3_get_table() routine does not have access
3131** to any internal data structures of SQLite. It uses only the public
3132** interface defined here. As a consequence, errors that occur in the
3133** wrapper layer outside of the internal [sqlite3_exec()] call are not
3134** reflected in subsequent calls to [sqlite3_errcode()] or
3135** [sqlite3_errmsg()].
3136*/
3137SQLITE_API int sqlite3_get_table(
3138 sqlite3 *db, /* An open database */
3139 const char *zSql, /* SQL to be evaluated */
3140 char ***pazResult, /* Results of the query */
3141 int *pnRow, /* Number of result rows written here */
3142 int *pnColumn, /* Number of result columns written here */
3143 char **pzErrmsg /* Error msg written here */
3144);
3145SQLITE_API void sqlite3_free_table(char **result);
3146
3147/*
3148** CAPI3REF: Formatted String Printing Functions
3149**
3150** These routines are work-alikes of the "printf()" family of functions
3151** from the standard C library.
3152** These routines understand most of the common formatting options from
3153** the standard library printf()
3154** plus some additional non-standard formats ([%q], [%Q], [%w], and [%z]).
3155** See the [built-in printf()] documentation for details.
3156**
3157** ^The sqlite3_mprintf() and sqlite3_vmprintf() routines write their
3158** results into memory obtained from [sqlite3_malloc64()].
3159** The strings returned by these two routines should be
3160** released by [sqlite3_free()]. ^Both routines return a
3161** NULL pointer if [sqlite3_malloc64()] is unable to allocate enough
3162** memory to hold the resulting string.
3163**
3164** ^(The sqlite3_snprintf() routine is similar to "snprintf()" from
3165** the standard C library. The result is written into the
3166** buffer supplied as the second parameter whose size is given by
3167** the first parameter. Note that the order of the
3168** first two parameters is reversed from snprintf().)^ This is an
3169** historical accident that cannot be fixed without breaking
3170** backwards compatibility. ^(Note also that sqlite3_snprintf()
3171** returns a pointer to its buffer instead of the number of
3172** characters actually written into the buffer.)^ We admit that
3173** the number of characters written would be a more useful return
3174** value but we cannot change the implementation of sqlite3_snprintf()
3175** now without breaking compatibility.
3176**
3177** ^As long as the buffer size is greater than zero, sqlite3_snprintf()
3178** guarantees that the buffer is always zero-terminated. ^The first
3179** parameter "n" is the total size of the buffer, including space for
3180** the zero terminator. So the longest string that can be completely
3181** written will be n-1 characters.
3182**
3183** ^The sqlite3_vsnprintf() routine is a varargs version of sqlite3_snprintf().
3184**
3185** See also: [built-in printf()], [printf() SQL function]
3186*/
3187SQLITE_API char *sqlite3_mprintf(const char*,...);
3188SQLITE_API char *sqlite3_vmprintf(const char*, va_list);
3189SQLITE_API char *sqlite3_snprintf(int,char*,const char*, ...);
3190SQLITE_API char *sqlite3_vsnprintf(int,char*,const char*, va_list);
3191
3192/*
3193** CAPI3REF: Memory Allocation Subsystem
3194**
3195** The SQLite core uses these three routines for all of its own
3196** internal memory allocation needs. "Core" in the previous sentence
3197** does not include operating-system specific [VFS] implementation. The
3198** Windows VFS uses native malloc() and free() for some operations.
3199**
3200** ^The sqlite3_malloc() routine returns a pointer to a block
3201** of memory at least N bytes in length, where N is the parameter.
3202** ^If sqlite3_malloc() is unable to obtain sufficient free
3203** memory, it returns a NULL pointer. ^If the parameter N to
3204** sqlite3_malloc() is zero or negative then sqlite3_malloc() returns
3205** a NULL pointer.
3206**
3207** ^The sqlite3_malloc64(N) routine works just like
3208** sqlite3_malloc(N) except that N is an unsigned 64-bit integer instead
3209** of a signed 32-bit integer.
3210**
3211** ^Calling sqlite3_free() with a pointer previously returned
3212** by sqlite3_malloc() or sqlite3_realloc() releases that memory so
3213** that it might be reused. ^The sqlite3_free() routine is
3214** a no-op if is called with a NULL pointer. Passing a NULL pointer
3215** to sqlite3_free() is harmless. After being freed, memory
3216** should neither be read nor written. Even reading previously freed
3217** memory might result in a segmentation fault or other severe error.
3218** Memory corruption, a segmentation fault, or other severe error
3219** might result if sqlite3_free() is called with a non-NULL pointer that
3220** was not obtained from sqlite3_malloc() or sqlite3_realloc().
3221**
3222** ^The sqlite3_realloc(X,N) interface attempts to resize a
3223** prior memory allocation X to be at least N bytes.
3224** ^If the X parameter to sqlite3_realloc(X,N)
3225** is a NULL pointer then its behavior is identical to calling
3226** sqlite3_malloc(N).
3227** ^If the N parameter to sqlite3_realloc(X,N) is zero or
3228** negative then the behavior is exactly the same as calling
3229** sqlite3_free(X).
3230** ^sqlite3_realloc(X,N) returns a pointer to a memory allocation
3231** of at least N bytes in size or NULL if insufficient memory is available.
3232** ^If M is the size of the prior allocation, then min(N,M) bytes
3233** of the prior allocation are copied into the beginning of buffer returned
3234** by sqlite3_realloc(X,N) and the prior allocation is freed.
3235** ^If sqlite3_realloc(X,N) returns NULL and N is positive, then the
3236** prior allocation is not freed.
3237**
3238** ^The sqlite3_realloc64(X,N) interfaces works the same as
3239** sqlite3_realloc(X,N) except that N is a 64-bit unsigned integer instead
3240** of a 32-bit signed integer.
3241**
3242** ^If X is a memory allocation previously obtained from sqlite3_malloc(),
3243** sqlite3_malloc64(), sqlite3_realloc(), or sqlite3_realloc64(), then
3244** sqlite3_msize(X) returns the size of that memory allocation in bytes.
3245** ^The value returned by sqlite3_msize(X) might be larger than the number
3246** of bytes requested when X was allocated. ^If X is a NULL pointer then
3247** sqlite3_msize(X) returns zero. If X points to something that is not
3248** the beginning of memory allocation, or if it points to a formerly
3249** valid memory allocation that has now been freed, then the behavior
3250** of sqlite3_msize(X) is undefined and possibly harmful.
3251**
3252** ^The memory returned by sqlite3_malloc(), sqlite3_realloc(),
3253** sqlite3_malloc64(), and sqlite3_realloc64()
3254** is always aligned to at least an 8 byte boundary, or to a
3255** 4 byte boundary if the [SQLITE_4_BYTE_ALIGNED_MALLOC] compile-time
3256** option is used.
3257**
3258** The pointer arguments to [sqlite3_free()] and [sqlite3_realloc()]
3259** must be either NULL or else pointers obtained from a prior
3260** invocation of [sqlite3_malloc()] or [sqlite3_realloc()] that have
3261** not yet been released.
3262**
3263** The application must not read or write any part of
3264** a block of memory after it has been released using
3265** [sqlite3_free()] or [sqlite3_realloc()].
3266*/
3267SQLITE_API void *sqlite3_malloc(int);
3268SQLITE_API void *sqlite3_malloc64(sqlite3_uint64);
3269SQLITE_API void *sqlite3_realloc(void*, int);
3270SQLITE_API void *sqlite3_realloc64(void*, sqlite3_uint64);
3271SQLITE_API void sqlite3_free(void*);
3272SQLITE_API sqlite3_uint64 sqlite3_msize(void*);
3273
3274/*
3275** CAPI3REF: Memory Allocator Statistics
3276**
3277** SQLite provides these two interfaces for reporting on the status
3278** of the [sqlite3_malloc()], [sqlite3_free()], and [sqlite3_realloc()]
3279** routines, which form the built-in memory allocation subsystem.
3280**
3281** ^The [sqlite3_memory_used()] routine returns the number of bytes
3282** of memory currently outstanding (malloced but not freed).
3283** ^The [sqlite3_memory_highwater()] routine returns the maximum
3284** value of [sqlite3_memory_used()] since the high-water mark
3285** was last reset. ^The values returned by [sqlite3_memory_used()] and
3286** [sqlite3_memory_highwater()] include any overhead
3287** added by SQLite in its implementation of [sqlite3_malloc()],
3288** but not overhead added by the any underlying system library
3289** routines that [sqlite3_malloc()] may call.
3290**
3291** ^The memory high-water mark is reset to the current value of
3292** [sqlite3_memory_used()] if and only if the parameter to
3293** [sqlite3_memory_highwater()] is true. ^The value returned
3294** by [sqlite3_memory_highwater(1)] is the high-water mark
3295** prior to the reset.
3296*/
3297SQLITE_API sqlite3_int64 sqlite3_memory_used(void);
3298SQLITE_API sqlite3_int64 sqlite3_memory_highwater(int resetFlag);
3299
3300/*
3301** CAPI3REF: Pseudo-Random Number Generator
3302**
3303** SQLite contains a high-quality pseudo-random number generator (PRNG) used to
3304** select random [ROWID | ROWIDs] when inserting new records into a table that
3305** already uses the largest possible [ROWID]. The PRNG is also used for
3306** the built-in random() and randomblob() SQL functions. This interface allows
3307** applications to access the same PRNG for other purposes.
3308**
3309** ^A call to this routine stores N bytes of randomness into buffer P.
3310** ^The P parameter can be a NULL pointer.
3311**
3312** ^If this routine has not been previously called or if the previous
3313** call had N less than one or a NULL pointer for P, then the PRNG is
3314** seeded using randomness obtained from the xRandomness method of
3315** the default [sqlite3_vfs] object.
3316** ^If the previous call to this routine had an N of 1 or more and a
3317** non-NULL P then the pseudo-randomness is generated
3318** internally and without recourse to the [sqlite3_vfs] xRandomness
3319** method.
3320*/
3321SQLITE_API void sqlite3_randomness(int N, void *P);
3322
3323/*
3324** CAPI3REF: Compile-Time Authorization Callbacks
3325** METHOD: sqlite3
3326** KEYWORDS: {authorizer callback}
3327**
3328** ^This routine registers an authorizer callback with a particular
3329** [database connection], supplied in the first argument.
3330** ^The authorizer callback is invoked as SQL statements are being compiled
3331** by [sqlite3_prepare()] or its variants [sqlite3_prepare_v2()],
3332** [sqlite3_prepare_v3()], [sqlite3_prepare16()], [sqlite3_prepare16_v2()],
3333** and [sqlite3_prepare16_v3()]. ^At various
3334** points during the compilation process, as logic is being created
3335** to perform various actions, the authorizer callback is invoked to
3336** see if those actions are allowed. ^The authorizer callback should
3337** return [SQLITE_OK] to allow the action, [SQLITE_IGNORE] to disallow the
3338** specific action but allow the SQL statement to continue to be
3339** compiled, or [SQLITE_DENY] to cause the entire SQL statement to be
3340** rejected with an error. ^If the authorizer callback returns
3341** any value other than [SQLITE_IGNORE], [SQLITE_OK], or [SQLITE_DENY]
3342** then the [sqlite3_prepare_v2()] or equivalent call that triggered
3343** the authorizer will fail with an error message.
3344**
3345** When the callback returns [SQLITE_OK], that means the operation
3346** requested is ok. ^When the callback returns [SQLITE_DENY], the
3347** [sqlite3_prepare_v2()] or equivalent call that triggered the
3348** authorizer will fail with an error message explaining that
3349** access is denied.
3350**
3351** ^The first parameter to the authorizer callback is a copy of the third
3352** parameter to the sqlite3_set_authorizer() interface. ^The second parameter
3353** to the callback is an integer [SQLITE_COPY | action code] that specifies
3354** the particular action to be authorized. ^The third through sixth parameters
3355** to the callback are either NULL pointers or zero-terminated strings
3356** that contain additional details about the action to be authorized.
3357** Applications must always be prepared to encounter a NULL pointer in any
3358** of the third through the sixth parameters of the authorization callback.
3359**
3360** ^If the action code is [SQLITE_READ]
3361** and the callback returns [SQLITE_IGNORE] then the
3362** [prepared statement] statement is constructed to substitute
3363** a NULL value in place of the table column that would have
3364** been read if [SQLITE_OK] had been returned. The [SQLITE_IGNORE]
3365** return can be used to deny an untrusted user access to individual
3366** columns of a table.
3367** ^When a table is referenced by a [SELECT] but no column values are
3368** extracted from that table (for example in a query like
3369** "SELECT count(*) FROM tab") then the [SQLITE_READ] authorizer callback
3370** is invoked once for that table with a column name that is an empty string.
3371** ^If the action code is [SQLITE_DELETE] and the callback returns
3372** [SQLITE_IGNORE] then the [DELETE] operation proceeds but the
3373** [truncate optimization] is disabled and all rows are deleted individually.
3374**
3375** An authorizer is used when [sqlite3_prepare | preparing]
3376** SQL statements from an untrusted source, to ensure that the SQL statements
3377** do not try to access data they are not allowed to see, or that they do not
3378** try to execute malicious statements that damage the database. For
3379** example, an application may allow a user to enter arbitrary
3380** SQL queries for evaluation by a database. But the application does
3381** not want the user to be able to make arbitrary changes to the
3382** database. An authorizer could then be put in place while the
3383** user-entered SQL is being [sqlite3_prepare | prepared] that
3384** disallows everything except [SELECT] statements.
3385**
3386** Applications that need to process SQL from untrusted sources
3387** might also consider lowering resource limits using [sqlite3_limit()]
3388** and limiting database size using the [max_page_count] [PRAGMA]
3389** in addition to using an authorizer.
3390**
3391** ^(Only a single authorizer can be in place on a database connection
3392** at a time. Each call to sqlite3_set_authorizer overrides the
3393** previous call.)^ ^Disable the authorizer by installing a NULL callback.
3394** The authorizer is disabled by default.
3395**
3396** The authorizer callback must not do anything that will modify
3397** the database connection that invoked the authorizer callback.
3398** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their
3399** database connections for the meaning of "modify" in this paragraph.
3400**
3401** ^When [sqlite3_prepare_v2()] is used to prepare a statement, the
3402** statement might be re-prepared during [sqlite3_step()] due to a
3403** schema change. Hence, the application should ensure that the
3404** correct authorizer callback remains in place during the [sqlite3_step()].
3405**
3406** ^Note that the authorizer callback is invoked only during
3407** [sqlite3_prepare()] or its variants. Authorization is not
3408** performed during statement evaluation in [sqlite3_step()], unless
3409** as stated in the previous paragraph, sqlite3_step() invokes
3410** sqlite3_prepare_v2() to reprepare a statement after a schema change.
3411*/
3412SQLITE_API int sqlite3_set_authorizer(
3413 sqlite3*,
3414 int (*xAuth)(void*,int,const char*,const char*,const char*,const char*),
3415 void *pUserData
3416);
3417
3418/*
3419** CAPI3REF: Authorizer Return Codes
3420**
3421** The [sqlite3_set_authorizer | authorizer callback function] must
3422** return either [SQLITE_OK] or one of these two constants in order
3423** to signal SQLite whether or not the action is permitted. See the
3424** [sqlite3_set_authorizer | authorizer documentation] for additional
3425** information.
3426**
3427** Note that SQLITE_IGNORE is also used as a [conflict resolution mode]
3428** returned from the [sqlite3_vtab_on_conflict()] interface.
3429*/
3430#define SQLITE_DENY 1 /* Abort the SQL statement with an error */
3431#define SQLITE_IGNORE 2 /* Don't allow access, but don't generate an error */
3432
3433/*
3434** CAPI3REF: Authorizer Action Codes
3435**
3436** The [sqlite3_set_authorizer()] interface registers a callback function
3437** that is invoked to authorize certain SQL statement actions. The
3438** second parameter to the callback is an integer code that specifies
3439** what action is being authorized. These are the integer action codes that
3440** the authorizer callback may be passed.
3441**
3442** These action code values signify what kind of operation is to be
3443** authorized. The 3rd and 4th parameters to the authorization
3444** callback function will be parameters or NULL depending on which of these
3445** codes is used as the second parameter. ^(The 5th parameter to the
3446** authorizer callback is the name of the database ("main", "temp",
3447** etc.) if applicable.)^ ^The 6th parameter to the authorizer callback
3448** is the name of the inner-most trigger or view that is responsible for
3449** the access attempt or NULL if this access attempt is directly from
3450** top-level SQL code.
3451*/
3452/******************************************* 3rd ************ 4th ***********/
3453#define SQLITE_CREATE_INDEX 1 /* Index Name Table Name */
3454#define SQLITE_CREATE_TABLE 2 /* Table Name NULL */
3455#define SQLITE_CREATE_TEMP_INDEX 3 /* Index Name Table Name */
3456#define SQLITE_CREATE_TEMP_TABLE 4 /* Table Name NULL */
3457#define SQLITE_CREATE_TEMP_TRIGGER 5 /* Trigger Name Table Name */
3458#define SQLITE_CREATE_TEMP_VIEW 6 /* View Name NULL */
3459#define SQLITE_CREATE_TRIGGER 7 /* Trigger Name Table Name */
3460#define SQLITE_CREATE_VIEW 8 /* View Name NULL */
3461#define SQLITE_DELETE 9 /* Table Name NULL */
3462#define SQLITE_DROP_INDEX 10 /* Index Name Table Name */
3463#define SQLITE_DROP_TABLE 11 /* Table Name NULL */
3464#define SQLITE_DROP_TEMP_INDEX 12 /* Index Name Table Name */
3465#define SQLITE_DROP_TEMP_TABLE 13 /* Table Name NULL */
3466#define SQLITE_DROP_TEMP_TRIGGER 14 /* Trigger Name Table Name */
3467#define SQLITE_DROP_TEMP_VIEW 15 /* View Name NULL */
3468#define SQLITE_DROP_TRIGGER 16 /* Trigger Name Table Name */
3469#define SQLITE_DROP_VIEW 17 /* View Name NULL */
3470#define SQLITE_INSERT 18 /* Table Name NULL */
3471#define SQLITE_PRAGMA 19 /* Pragma Name 1st arg or NULL */
3472#define SQLITE_READ 20 /* Table Name Column Name */
3473#define SQLITE_SELECT 21 /* NULL NULL */
3474#define SQLITE_TRANSACTION 22 /* Operation NULL */
3475#define SQLITE_UPDATE 23 /* Table Name Column Name */
3476#define SQLITE_ATTACH 24 /* Filename NULL */
3477#define SQLITE_DETACH 25 /* Database Name NULL */
3478#define SQLITE_ALTER_TABLE 26 /* Database Name Table Name */
3479#define SQLITE_REINDEX 27 /* Index Name NULL */
3480#define SQLITE_ANALYZE 28 /* Table Name NULL */
3481#define SQLITE_CREATE_VTABLE 29 /* Table Name Module Name */
3482#define SQLITE_DROP_VTABLE 30 /* Table Name Module Name */
3483#define SQLITE_FUNCTION 31 /* NULL Function Name */
3484#define SQLITE_SAVEPOINT 32 /* Operation Savepoint Name */
3485#define SQLITE_COPY 0 /* No longer used */
3486#define SQLITE_RECURSIVE 33 /* NULL NULL */
3487
3488/*
3489** CAPI3REF: Deprecated Tracing And Profiling Functions
3490** DEPRECATED
3491**
3492** These routines are deprecated. Use the [sqlite3_trace_v2()] interface
3493** instead of the routines described here.
3494**
3495** These routines register callback functions that can be used for
3496** tracing and profiling the execution of SQL statements.
3497**
3498** ^The callback function registered by sqlite3_trace() is invoked at
3499** various times when an SQL statement is being run by [sqlite3_step()].
3500** ^The sqlite3_trace() callback is invoked with a UTF-8 rendering of the
3501** SQL statement text as the statement first begins executing.
3502** ^(Additional sqlite3_trace() callbacks might occur
3503** as each triggered subprogram is entered. The callbacks for triggers
3504** contain a UTF-8 SQL comment that identifies the trigger.)^
3505**
3506** The [SQLITE_TRACE_SIZE_LIMIT] compile-time option can be used to limit
3507** the length of [bound parameter] expansion in the output of sqlite3_trace().
3508**
3509** ^The callback function registered by sqlite3_profile() is invoked
3510** as each SQL statement finishes. ^The profile callback contains
3511** the original statement text and an estimate of wall-clock time
3512** of how long that statement took to run. ^The profile callback
3513** time is in units of nanoseconds, however the current implementation
3514** is only capable of millisecond resolution so the six least significant
3515** digits in the time are meaningless. Future versions of SQLite
3516** might provide greater resolution on the profiler callback. Invoking
3517** either [sqlite3_trace()] or [sqlite3_trace_v2()] will cancel the
3518** profile callback.
3519*/
3520SQLITE_API SQLITE_DEPRECATED void *sqlite3_trace(sqlite3*,
3521 void(*xTrace)(void*,const char*), void*);
3522SQLITE_API SQLITE_DEPRECATED void *sqlite3_profile(sqlite3*,
3523 void(*xProfile)(void*,const char*,sqlite3_uint64), void*);
3524
3525/*
3526** CAPI3REF: SQL Trace Event Codes
3527** KEYWORDS: SQLITE_TRACE
3528**
3529** These constants identify classes of events that can be monitored
3530** using the [sqlite3_trace_v2()] tracing logic. The M argument
3531** to [sqlite3_trace_v2(D,M,X,P)] is an OR-ed combination of one or more of
3532** the following constants. ^The first argument to the trace callback
3533** is one of the following constants.
3534**
3535** New tracing constants may be added in future releases.
3536**
3537** ^A trace callback has four arguments: xCallback(T,C,P,X).
3538** ^The T argument is one of the integer type codes above.
3539** ^The C argument is a copy of the context pointer passed in as the
3540** fourth argument to [sqlite3_trace_v2()].
3541** The P and X arguments are pointers whose meanings depend on T.
3542**
3543** <dl>
3544** [[SQLITE_TRACE_STMT]] <dt>SQLITE_TRACE_STMT</dt>
3545** <dd>^An SQLITE_TRACE_STMT callback is invoked when a prepared statement
3546** first begins running and possibly at other times during the
3547** execution of the prepared statement, such as at the start of each
3548** trigger subprogram. ^The P argument is a pointer to the
3549** [prepared statement]. ^The X argument is a pointer to a string which
3550** is the unexpanded SQL text of the prepared statement or an SQL comment
3551** that indicates the invocation of a trigger. ^The callback can compute
3552** the same text that would have been returned by the legacy [sqlite3_trace()]
3553** interface by using the X argument when X begins with "--" and invoking
3554** [sqlite3_expanded_sql(P)] otherwise.
3555**
3556** [[SQLITE_TRACE_PROFILE]] <dt>SQLITE_TRACE_PROFILE</dt>
3557** <dd>^An SQLITE_TRACE_PROFILE callback provides approximately the same
3558** information as is provided by the [sqlite3_profile()] callback.
3559** ^The P argument is a pointer to the [prepared statement] and the
3560** X argument points to a 64-bit integer which is approximately
3561** the number of nanoseconds that the prepared statement took to run.
3562** ^The SQLITE_TRACE_PROFILE callback is invoked when the statement finishes.
3563**
3564** [[SQLITE_TRACE_ROW]] <dt>SQLITE_TRACE_ROW</dt>
3565** <dd>^An SQLITE_TRACE_ROW callback is invoked whenever a prepared
3566** statement generates a single row of result.
3567** ^The P argument is a pointer to the [prepared statement] and the
3568** X argument is unused.
3569**
3570** [[SQLITE_TRACE_CLOSE]] <dt>SQLITE_TRACE_CLOSE</dt>
3571** <dd>^An SQLITE_TRACE_CLOSE callback is invoked when a database
3572** connection closes.
3573** ^The P argument is a pointer to the [database connection] object
3574** and the X argument is unused.
3575** </dl>
3576*/
3577#define SQLITE_TRACE_STMT 0x01
3578#define SQLITE_TRACE_PROFILE 0x02
3579#define SQLITE_TRACE_ROW 0x04
3580#define SQLITE_TRACE_CLOSE 0x08
3581
3582/*
3583** CAPI3REF: SQL Trace Hook
3584** METHOD: sqlite3
3585**
3586** ^The sqlite3_trace_v2(D,M,X,P) interface registers a trace callback
3587** function X against [database connection] D, using property mask M
3588** and context pointer P. ^If the X callback is
3589** NULL or if the M mask is zero, then tracing is disabled. The
3590** M argument should be the bitwise OR-ed combination of
3591** zero or more [SQLITE_TRACE] constants.
3592**
3593** ^Each call to either sqlite3_trace(D,X,P) or sqlite3_trace_v2(D,M,X,P)
3594** overrides (cancels) all prior calls to sqlite3_trace(D,X,P) or
3595** sqlite3_trace_v2(D,M,X,P) for the [database connection] D. Each
3596** database connection may have at most one trace callback.
3597**
3598** ^The X callback is invoked whenever any of the events identified by
3599** mask M occur. ^The integer return value from the callback is currently
3600** ignored, though this may change in future releases. Callback
3601** implementations should return zero to ensure future compatibility.
3602**
3603** ^A trace callback is invoked with four arguments: callback(T,C,P,X).
3604** ^The T argument is one of the [SQLITE_TRACE]
3605** constants to indicate why the callback was invoked.
3606** ^The C argument is a copy of the context pointer.
3607** The P and X arguments are pointers whose meanings depend on T.
3608**
3609** The sqlite3_trace_v2() interface is intended to replace the legacy
3610** interfaces [sqlite3_trace()] and [sqlite3_profile()], both of which
3611** are deprecated.
3612*/
3613SQLITE_API int sqlite3_trace_v2(
3614 sqlite3*,
3615 unsigned uMask,
3616 int(*xCallback)(unsigned,void*,void*,void*),
3617 void *pCtx
3618);
3619
3620/*
3621** CAPI3REF: Query Progress Callbacks
3622** METHOD: sqlite3
3623**
3624** ^The sqlite3_progress_handler(D,N,X,P) interface causes the callback
3625** function X to be invoked periodically during long running calls to
3626** [sqlite3_step()] and [sqlite3_prepare()] and similar for
3627** database connection D. An example use for this
3628** interface is to keep a GUI updated during a large query.
3629**
3630** ^The parameter P is passed through as the only parameter to the
3631** callback function X. ^The parameter N is the approximate number of
3632** [virtual machine instructions] that are evaluated between successive
3633** invocations of the callback X. ^If N is less than one then the progress
3634** handler is disabled.
3635**
3636** ^Only a single progress handler may be defined at one time per
3637** [database connection]; setting a new progress handler cancels the
3638** old one. ^Setting parameter X to NULL disables the progress handler.
3639** ^The progress handler is also disabled by setting N to a value less
3640** than 1.
3641**
3642** ^If the progress callback returns non-zero, the operation is
3643** interrupted. This feature can be used to implement a
3644** "Cancel" button on a GUI progress dialog box.
3645**
3646** The progress handler callback must not do anything that will modify
3647** the database connection that invoked the progress handler.
3648** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their
3649** database connections for the meaning of "modify" in this paragraph.
3650**
3651** The progress handler callback would originally only be invoked from the
3652** bytecode engine. It still might be invoked during [sqlite3_prepare()]
3653** and similar because those routines might force a reparse of the schema
3654** which involves running the bytecode engine. However, beginning with
3655** SQLite version 3.41.0, the progress handler callback might also be
3656** invoked directly from [sqlite3_prepare()] while analyzing and generating
3657** code for complex queries.
3658*/
3659SQLITE_API void sqlite3_progress_handler(sqlite3*, int, int(*)(void*), void*);
3660
3661/*
3662** CAPI3REF: Opening A New Database Connection
3663** CONSTRUCTOR: sqlite3
3664**
3665** ^These routines open an SQLite database file as specified by the
3666** filename argument. ^The filename argument is interpreted as UTF-8 for
3667** sqlite3_open() and sqlite3_open_v2() and as UTF-16 in the native byte
3668** order for sqlite3_open16(). ^(A [database connection] handle is usually
3669** returned in *ppDb, even if an error occurs. The only exception is that
3670** if SQLite is unable to allocate memory to hold the [sqlite3] object,
3671** a NULL will be written into *ppDb instead of a pointer to the [sqlite3]
3672** object.)^ ^(If the database is opened (and/or created) successfully, then
3673** [SQLITE_OK] is returned. Otherwise an [error code] is returned.)^ ^The
3674** [sqlite3_errmsg()] or [sqlite3_errmsg16()] routines can be used to obtain
3675** an English language description of the error following a failure of any
3676** of the sqlite3_open() routines.
3677**
3678** ^The default encoding will be UTF-8 for databases created using
3679** sqlite3_open() or sqlite3_open_v2(). ^The default encoding for databases
3680** created using sqlite3_open16() will be UTF-16 in the native byte order.
3681**
3682** Whether or not an error occurs when it is opened, resources
3683** associated with the [database connection] handle should be released by
3684** passing it to [sqlite3_close()] when it is no longer required.
3685**
3686** The sqlite3_open_v2() interface works like sqlite3_open()
3687** except that it accepts two additional parameters for additional control
3688** over the new database connection. ^(The flags parameter to
3689** sqlite3_open_v2() must include, at a minimum, one of the following
3690** three flag combinations:)^
3691**
3692** <dl>
3693** ^(<dt>[SQLITE_OPEN_READONLY]</dt>
3694** <dd>The database is opened in read-only mode. If the database does
3695** not already exist, an error is returned.</dd>)^
3696**
3697** ^(<dt>[SQLITE_OPEN_READWRITE]</dt>
3698** <dd>The database is opened for reading and writing if possible, or
3699** reading only if the file is write protected by the operating
3700** system. In either case the database must already exist, otherwise
3701** an error is returned. For historical reasons, if opening in
3702** read-write mode fails due to OS-level permissions, an attempt is
3703** made to open it in read-only mode. [sqlite3_db_readonly()] can be
3704** used to determine whether the database is actually
3705** read-write.</dd>)^
3706**
3707** ^(<dt>[SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]</dt>
3708** <dd>The database is opened for reading and writing, and is created if
3709** it does not already exist. This is the behavior that is always used for
3710** sqlite3_open() and sqlite3_open16().</dd>)^
3711** </dl>
3712**
3713** In addition to the required flags, the following optional flags are
3714** also supported:
3715**
3716** <dl>
3717** ^(<dt>[SQLITE_OPEN_URI]</dt>
3718** <dd>The filename can be interpreted as a URI if this flag is set.</dd>)^
3719**
3720** ^(<dt>[SQLITE_OPEN_MEMORY]</dt>
3721** <dd>The database will be opened as an in-memory database. The database
3722** is named by the "filename" argument for the purposes of cache-sharing,
3723** if shared cache mode is enabled, but the "filename" is otherwise ignored.
3724** </dd>)^
3725**
3726** ^(<dt>[SQLITE_OPEN_NOMUTEX]</dt>
3727** <dd>The new database connection will use the "multi-thread"
3728** [threading mode].)^ This means that separate threads are allowed
3729** to use SQLite at the same time, as long as each thread is using
3730** a different [database connection].
3731**
3732** ^(<dt>[SQLITE_OPEN_FULLMUTEX]</dt>
3733** <dd>The new database connection will use the "serialized"
3734** [threading mode].)^ This means the multiple threads can safely
3735** attempt to use the same database connection at the same time.
3736** (Mutexes will block any actual concurrency, but in this mode
3737** there is no harm in trying.)
3738**
3739** ^(<dt>[SQLITE_OPEN_SHAREDCACHE]</dt>
3740** <dd>The database is opened [shared cache] enabled, overriding
3741** the default shared cache setting provided by
3742** [sqlite3_enable_shared_cache()].)^
3743** The [use of shared cache mode is discouraged] and hence shared cache
3744** capabilities may be omitted from many builds of SQLite. In such cases,
3745** this option is a no-op.
3746**
3747** ^(<dt>[SQLITE_OPEN_PRIVATECACHE]</dt>
3748** <dd>The database is opened [shared cache] disabled, overriding
3749** the default shared cache setting provided by
3750** [sqlite3_enable_shared_cache()].)^
3751**
3752** [[OPEN_EXRESCODE]] ^(<dt>[SQLITE_OPEN_EXRESCODE]</dt>
3753** <dd>The database connection comes up in "extended result code mode".
3754** In other words, the database behaves as if
3755** [sqlite3_extended_result_codes(db,1)] were called on the database
3756** connection as soon as the connection is created. In addition to setting
3757** the extended result code mode, this flag also causes [sqlite3_open_v2()]
3758** to return an extended result code.</dd>
3759**
3760** [[OPEN_NOFOLLOW]] ^(<dt>[SQLITE_OPEN_NOFOLLOW]</dt>
3761** <dd>The database filename is not allowed to contain a symbolic link</dd>
3762** </dl>)^
3763**
3764** If the 3rd parameter to sqlite3_open_v2() is not one of the
3765** required combinations shown above optionally combined with other
3766** [SQLITE_OPEN_READONLY | SQLITE_OPEN_* bits]
3767** then the behavior is undefined. Historic versions of SQLite
3768** have silently ignored surplus bits in the flags parameter to
3769** sqlite3_open_v2(), however that behavior might not be carried through
3770** into future versions of SQLite and so applications should not rely
3771** upon it. Note in particular that the SQLITE_OPEN_EXCLUSIVE flag is a no-op
3772** for sqlite3_open_v2(). The SQLITE_OPEN_EXCLUSIVE does *not* cause
3773** the open to fail if the database already exists. The SQLITE_OPEN_EXCLUSIVE
3774** flag is intended for use by the [sqlite3_vfs|VFS interface] only, and not
3775** by sqlite3_open_v2().
3776**
3777** ^The fourth parameter to sqlite3_open_v2() is the name of the
3778** [sqlite3_vfs] object that defines the operating system interface that
3779** the new database connection should use. ^If the fourth parameter is
3780** a NULL pointer then the default [sqlite3_vfs] object is used.
3781**
3782** ^If the filename is ":memory:", then a private, temporary in-memory database
3783** is created for the connection. ^This in-memory database will vanish when
3784** the database connection is closed. Future versions of SQLite might
3785** make use of additional special filenames that begin with the ":" character.
3786** It is recommended that when a database filename actually does begin with
3787** a ":" character you should prefix the filename with a pathname such as
3788** "./" to avoid ambiguity.
3789**
3790** ^If the filename is an empty string, then a private, temporary
3791** on-disk database will be created. ^This private database will be
3792** automatically deleted as soon as the database connection is closed.
3793**
3794** [[URI filenames in sqlite3_open()]] <h3>URI Filenames</h3>
3795**
3796** ^If [URI filename] interpretation is enabled, and the filename argument
3797** begins with "file:", then the filename is interpreted as a URI. ^URI
3798** filename interpretation is enabled if the [SQLITE_OPEN_URI] flag is
3799** set in the third argument to sqlite3_open_v2(), or if it has
3800** been enabled globally using the [SQLITE_CONFIG_URI] option with the
3801** [sqlite3_config()] method or by the [SQLITE_USE_URI] compile-time option.
3802** URI filename interpretation is turned off
3803** by default, but future releases of SQLite might enable URI filename
3804** interpretation by default. See "[URI filenames]" for additional
3805** information.
3806**
3807** URI filenames are parsed according to RFC 3986. ^If the URI contains an
3808** authority, then it must be either an empty string or the string
3809** "localhost". ^If the authority is not an empty string or "localhost", an
3810** error is returned to the caller. ^The fragment component of a URI, if
3811** present, is ignored.
3812**
3813** ^SQLite uses the path component of the URI as the name of the disk file
3814** which contains the database. ^If the path begins with a '/' character,
3815** then it is interpreted as an absolute path. ^If the path does not begin
3816** with a '/' (meaning that the authority section is omitted from the URI)
3817** then the path is interpreted as a relative path.
3818** ^(On windows, the first component of an absolute path
3819** is a drive specification (e.g. "C:").)^
3820**
3821** [[core URI query parameters]]
3822** The query component of a URI may contain parameters that are interpreted
3823** either by SQLite itself, or by a [VFS | custom VFS implementation].
3824** SQLite and its built-in [VFSes] interpret the
3825** following query parameters:
3826**
3827** <ul>
3828** <li> <b>vfs</b>: ^The "vfs" parameter may be used to specify the name of
3829** a VFS object that provides the operating system interface that should
3830** be used to access the database file on disk. ^If this option is set to
3831** an empty string the default VFS object is used. ^Specifying an unknown
3832** VFS is an error. ^If sqlite3_open_v2() is used and the vfs option is
3833** present, then the VFS specified by the option takes precedence over
3834** the value passed as the fourth parameter to sqlite3_open_v2().
3835**
3836** <li> <b>mode</b>: ^(The mode parameter may be set to either "ro", "rw",
3837** "rwc", or "memory". Attempting to set it to any other value is
3838** an error)^.
3839** ^If "ro" is specified, then the database is opened for read-only
3840** access, just as if the [SQLITE_OPEN_READONLY] flag had been set in the
3841** third argument to sqlite3_open_v2(). ^If the mode option is set to
3842** "rw", then the database is opened for read-write (but not create)
3843** access, as if SQLITE_OPEN_READWRITE (but not SQLITE_OPEN_CREATE) had
3844** been set. ^Value "rwc" is equivalent to setting both
3845** SQLITE_OPEN_READWRITE and SQLITE_OPEN_CREATE. ^If the mode option is
3846** set to "memory" then a pure [in-memory database] that never reads
3847** or writes from disk is used. ^It is an error to specify a value for
3848** the mode parameter that is less restrictive than that specified by
3849** the flags passed in the third parameter to sqlite3_open_v2().
3850**
3851** <li> <b>cache</b>: ^The cache parameter may be set to either "shared" or
3852** "private". ^Setting it to "shared" is equivalent to setting the
3853** SQLITE_OPEN_SHAREDCACHE bit in the flags argument passed to
3854** sqlite3_open_v2(). ^Setting the cache parameter to "private" is
3855** equivalent to setting the SQLITE_OPEN_PRIVATECACHE bit.
3856** ^If sqlite3_open_v2() is used and the "cache" parameter is present in
3857** a URI filename, its value overrides any behavior requested by setting
3858** SQLITE_OPEN_PRIVATECACHE or SQLITE_OPEN_SHAREDCACHE flag.
3859**
3860** <li> <b>psow</b>: ^The psow parameter indicates whether or not the
3861** [powersafe overwrite] property does or does not apply to the
3862** storage media on which the database file resides.
3863**
3864** <li> <b>nolock</b>: ^The nolock parameter is a boolean query parameter
3865** which if set disables file locking in rollback journal modes. This
3866** is useful for accessing a database on a filesystem that does not
3867** support locking. Caution: Database corruption might result if two
3868** or more processes write to the same database and any one of those
3869** processes uses nolock=1.
3870**
3871** <li> <b>immutable</b>: ^The immutable parameter is a boolean query
3872** parameter that indicates that the database file is stored on
3873** read-only media. ^When immutable is set, SQLite assumes that the
3874** database file cannot be changed, even by a process with higher
3875** privilege, and so the database is opened read-only and all locking
3876** and change detection is disabled. Caution: Setting the immutable
3877** property on a database file that does in fact change can result
3878** in incorrect query results and/or [SQLITE_CORRUPT] errors.
3879** See also: [SQLITE_IOCAP_IMMUTABLE].
3880**
3881** </ul>
3882**
3883** ^Specifying an unknown parameter in the query component of a URI is not an
3884** error. Future versions of SQLite might understand additional query
3885** parameters. See "[query parameters with special meaning to SQLite]" for
3886** additional information.
3887**
3888** [[URI filename examples]] <h3>URI filename examples</h3>
3889**
3890** <table border="1" align=center cellpadding=5>
3891** <tr><th> URI filenames <th> Results
3892** <tr><td> file:data.db <td>
3893** Open the file "data.db" in the current directory.
3894** <tr><td> file:/home/fred/data.db<br>
3895** file:///home/fred/data.db <br>
3896** file://localhost/home/fred/data.db <br> <td>
3897** Open the database file "/home/fred/data.db".
3898** <tr><td> file://darkstar/home/fred/data.db <td>
3899** An error. "darkstar" is not a recognized authority.
3900** <tr><td style="white-space:nowrap">
3901** file:///C:/Documents%20and%20Settings/fred/Desktop/data.db
3902** <td> Windows only: Open the file "data.db" on fred's desktop on drive
3903** C:. Note that the %20 escaping in this example is not strictly
3904** necessary - space characters can be used literally
3905** in URI filenames.
3906** <tr><td> file:data.db?mode=ro&cache=private <td>
3907** Open file "data.db" in the current directory for read-only access.
3908** Regardless of whether or not shared-cache mode is enabled by
3909** default, use a private cache.
3910** <tr><td> file:/home/fred/data.db?vfs=unix-dotfile <td>
3911** Open file "/home/fred/data.db". Use the special VFS "unix-dotfile"
3912** that uses dot-files in place of posix advisory locking.
3913** <tr><td> file:data.db?mode=readonly <td>
3914** An error. "readonly" is not a valid option for the "mode" parameter.
3915** Use "ro" instead: "file:data.db?mode=ro".
3916** </table>
3917**
3918** ^URI hexadecimal escape sequences (%HH) are supported within the path and
3919** query components of a URI. A hexadecimal escape sequence consists of a
3920** percent sign - "%" - followed by exactly two hexadecimal digits
3921** specifying an octet value. ^Before the path or query components of a
3922** URI filename are interpreted, they are encoded using UTF-8 and all
3923** hexadecimal escape sequences replaced by a single byte containing the
3924** corresponding octet. If this process generates an invalid UTF-8 encoding,
3925** the results are undefined.
3926**
3927** <b>Note to Windows users:</b> The encoding used for the filename argument
3928** of sqlite3_open() and sqlite3_open_v2() must be UTF-8, not whatever
3929** codepage is currently defined. Filenames containing international
3930** characters must be converted to UTF-8 prior to passing them into
3931** sqlite3_open() or sqlite3_open_v2().
3932**
3933** <b>Note to Windows Runtime users:</b> The temporary directory must be set
3934** prior to calling sqlite3_open() or sqlite3_open_v2(). Otherwise, various
3935** features that require the use of temporary files may fail.
3936**
3937** See also: [sqlite3_temp_directory]
3938*/
3939SQLITE_API int sqlite3_open(
3940 const char *filename, /* Database filename (UTF-8) */
3941 sqlite3 **ppDb /* OUT: SQLite db handle */
3942);
3943SQLITE_API int sqlite3_open16(
3944 const void *filename, /* Database filename (UTF-16) */
3945 sqlite3 **ppDb /* OUT: SQLite db handle */
3946);
3947SQLITE_API int sqlite3_open_v2(
3948 const char *filename, /* Database filename (UTF-8) */
3949 sqlite3 **ppDb, /* OUT: SQLite db handle */
3950 int flags, /* Flags */
3951 const char *zVfs /* Name of VFS module to use */
3952);
3953
3954/*
3955** CAPI3REF: Obtain Values For URI Parameters
3956**
3957** These are utility routines, useful to [VFS|custom VFS implementations],
3958** that check if a database file was a URI that contained a specific query
3959** parameter, and if so obtains the value of that query parameter.
3960**
3961** The first parameter to these interfaces (hereafter referred to
3962** as F) must be one of:
3963** <ul>
3964** <li> A database filename pointer created by the SQLite core and
3965** passed into the xOpen() method of a VFS implementation, or
3966** <li> A filename obtained from [sqlite3_db_filename()], or
3967** <li> A new filename constructed using [sqlite3_create_filename()].
3968** </ul>
3969** If the F parameter is not one of the above, then the behavior is
3970** undefined and probably undesirable. Older versions of SQLite were
3971** more tolerant of invalid F parameters than newer versions.
3972**
3973** If F is a suitable filename (as described in the previous paragraph)
3974** and if P is the name of the query parameter, then
3975** sqlite3_uri_parameter(F,P) returns the value of the P
3976** parameter if it exists or a NULL pointer if P does not appear as a
3977** query parameter on F. If P is a query parameter of F and it
3978** has no explicit value, then sqlite3_uri_parameter(F,P) returns
3979** a pointer to an empty string.
3980**
3981** The sqlite3_uri_boolean(F,P,B) routine assumes that P is a boolean
3982** parameter and returns true (1) or false (0) according to the value
3983** of P. The sqlite3_uri_boolean(F,P,B) routine returns true (1) if the
3984** value of query parameter P is one of "yes", "true", or "on" in any
3985** case or if the value begins with a non-zero number. The
3986** sqlite3_uri_boolean(F,P,B) routines returns false (0) if the value of
3987** query parameter P is one of "no", "false", or "off" in any case or
3988** if the value begins with a numeric zero. If P is not a query
3989** parameter on F or if the value of P does not match any of the
3990** above, then sqlite3_uri_boolean(F,P,B) returns (B!=0).
3991**
3992** The sqlite3_uri_int64(F,P,D) routine converts the value of P into a
3993** 64-bit signed integer and returns that integer, or D if P does not
3994** exist. If the value of P is something other than an integer, then
3995** zero is returned.
3996**
3997** The sqlite3_uri_key(F,N) returns a pointer to the name (not
3998** the value) of the N-th query parameter for filename F, or a NULL
3999** pointer if N is less than zero or greater than the number of query
4000** parameters minus 1. The N value is zero-based so N should be 0 to obtain
4001** the name of the first query parameter, 1 for the second parameter, and
4002** so forth.
4003**
4004** If F is a NULL pointer, then sqlite3_uri_parameter(F,P) returns NULL and
4005** sqlite3_uri_boolean(F,P,B) returns B. If F is not a NULL pointer and
4006** is not a database file pathname pointer that the SQLite core passed
4007** into the xOpen VFS method, then the behavior of this routine is undefined
4008** and probably undesirable.
4009**
4010** Beginning with SQLite [version 3.31.0] ([dateof:3.31.0]) the input F
4011** parameter can also be the name of a rollback journal file or WAL file
4012** in addition to the main database file. Prior to version 3.31.0, these
4013** routines would only work if F was the name of the main database file.
4014** When the F parameter is the name of the rollback journal or WAL file,
4015** it has access to all the same query parameters as were found on the
4016** main database file.
4017**
4018** See the [URI filename] documentation for additional information.
4019*/
4020SQLITE_API const char *sqlite3_uri_parameter(sqlite3_filename z, const char *zParam);
4021SQLITE_API int sqlite3_uri_boolean(sqlite3_filename z, const char *zParam, int bDefault);
4022SQLITE_API sqlite3_int64 sqlite3_uri_int64(sqlite3_filename, const char*, sqlite3_int64);
4023SQLITE_API const char *sqlite3_uri_key(sqlite3_filename z, int N);
4024
4025/*
4026** CAPI3REF: Translate filenames
4027**
4028** These routines are available to [VFS|custom VFS implementations] for
4029** translating filenames between the main database file, the journal file,
4030** and the WAL file.
4031**
4032** If F is the name of an sqlite database file, journal file, or WAL file
4033** passed by the SQLite core into the VFS, then sqlite3_filename_database(F)
4034** returns the name of the corresponding database file.
4035**
4036** If F is the name of an sqlite database file, journal file, or WAL file
4037** passed by the SQLite core into the VFS, or if F is a database filename
4038** obtained from [sqlite3_db_filename()], then sqlite3_filename_journal(F)
4039** returns the name of the corresponding rollback journal file.
4040**
4041** If F is the name of an sqlite database file, journal file, or WAL file
4042** that was passed by the SQLite core into the VFS, or if F is a database
4043** filename obtained from [sqlite3_db_filename()], then
4044** sqlite3_filename_wal(F) returns the name of the corresponding
4045** WAL file.
4046**
4047** In all of the above, if F is not the name of a database, journal or WAL
4048** filename passed into the VFS from the SQLite core and F is not the
4049** return value from [sqlite3_db_filename()], then the result is
4050** undefined and is likely a memory access violation.
4051*/
4052SQLITE_API const char *sqlite3_filename_database(sqlite3_filename);
4053SQLITE_API const char *sqlite3_filename_journal(sqlite3_filename);
4054SQLITE_API const char *sqlite3_filename_wal(sqlite3_filename);
4055
4056/*
4057** CAPI3REF: Database File Corresponding To A Journal
4058**
4059** ^If X is the name of a rollback or WAL-mode journal file that is
4060** passed into the xOpen method of [sqlite3_vfs], then
4061** sqlite3_database_file_object(X) returns a pointer to the [sqlite3_file]
4062** object that represents the main database file.
4063**
4064** This routine is intended for use in custom [VFS] implementations
4065** only. It is not a general-purpose interface.
4066** The argument sqlite3_file_object(X) must be a filename pointer that
4067** has been passed into [sqlite3_vfs].xOpen method where the
4068** flags parameter to xOpen contains one of the bits
4069** [SQLITE_OPEN_MAIN_JOURNAL] or [SQLITE_OPEN_WAL]. Any other use
4070** of this routine results in undefined and probably undesirable
4071** behavior.
4072*/
4073SQLITE_API sqlite3_file *sqlite3_database_file_object(const char*);
4074
4075/*
4076** CAPI3REF: Create and Destroy VFS Filenames
4077**
4078** These interfaces are provided for use by [VFS shim] implementations and
4079** are not useful outside of that context.
4080**
4081** The sqlite3_create_filename(D,J,W,N,P) allocates memory to hold a version of
4082** database filename D with corresponding journal file J and WAL file W and
4083** an array P of N URI Key/Value pairs. The result from
4084** sqlite3_create_filename(D,J,W,N,P) is a pointer to a database filename that
4085** is safe to pass to routines like:
4086** <ul>
4087** <li> [sqlite3_uri_parameter()],
4088** <li> [sqlite3_uri_boolean()],
4089** <li> [sqlite3_uri_int64()],
4090** <li> [sqlite3_uri_key()],
4091** <li> [sqlite3_filename_database()],
4092** <li> [sqlite3_filename_journal()], or
4093** <li> [sqlite3_filename_wal()].
4094** </ul>
4095** If a memory allocation error occurs, sqlite3_create_filename() might
4096** return a NULL pointer. The memory obtained from sqlite3_create_filename(X)
4097** must be released by a corresponding call to sqlite3_free_filename(Y).
4098**
4099** The P parameter in sqlite3_create_filename(D,J,W,N,P) should be an array
4100** of 2*N pointers to strings. Each pair of pointers in this array corresponds
4101** to a key and value for a query parameter. The P parameter may be a NULL
4102** pointer if N is zero. None of the 2*N pointers in the P array may be
4103** NULL pointers and key pointers should not be empty strings.
4104** None of the D, J, or W parameters to sqlite3_create_filename(D,J,W,N,P) may
4105** be NULL pointers, though they can be empty strings.
4106**
4107** The sqlite3_free_filename(Y) routine releases a memory allocation
4108** previously obtained from sqlite3_create_filename(). Invoking
4109** sqlite3_free_filename(Y) where Y is a NULL pointer is a harmless no-op.
4110**
4111** If the Y parameter to sqlite3_free_filename(Y) is anything other
4112** than a NULL pointer or a pointer previously acquired from
4113** sqlite3_create_filename(), then bad things such as heap
4114** corruption or segfaults may occur. The value Y should not be
4115** used again after sqlite3_free_filename(Y) has been called. This means
4116** that if the [sqlite3_vfs.xOpen()] method of a VFS has been called using Y,
4117** then the corresponding [sqlite3_module.xClose() method should also be
4118** invoked prior to calling sqlite3_free_filename(Y).
4119*/
4120SQLITE_API sqlite3_filename sqlite3_create_filename(
4121 const char *zDatabase,
4122 const char *zJournal,
4123 const char *zWal,
4124 int nParam,
4125 const char **azParam
4126);
4127SQLITE_API void sqlite3_free_filename(sqlite3_filename);
4128
4129/*
4130** CAPI3REF: Error Codes And Messages
4131** METHOD: sqlite3
4132**
4133** ^If the most recent sqlite3_* API call associated with
4134** [database connection] D failed, then the sqlite3_errcode(D) interface
4135** returns the numeric [result code] or [extended result code] for that
4136** API call.
4137** ^The sqlite3_extended_errcode()
4138** interface is the same except that it always returns the
4139** [extended result code] even when extended result codes are
4140** disabled.
4141**
4142** The values returned by sqlite3_errcode() and/or
4143** sqlite3_extended_errcode() might change with each API call.
4144** Except, there are some interfaces that are guaranteed to never
4145** change the value of the error code. The error-code preserving
4146** interfaces include the following:
4147**
4148** <ul>
4149** <li> sqlite3_errcode()
4150** <li> sqlite3_extended_errcode()
4151** <li> sqlite3_errmsg()
4152** <li> sqlite3_errmsg16()
4153** <li> sqlite3_error_offset()
4154** </ul>
4155**
4156** ^The sqlite3_errmsg() and sqlite3_errmsg16() return English-language
4157** text that describes the error, as either UTF-8 or UTF-16 respectively,
4158** or NULL if no error message is available.
4159** (See how SQLite handles [invalid UTF] for exceptions to this rule.)
4160** ^(Memory to hold the error message string is managed internally.
4161** The application does not need to worry about freeing the result.
4162** However, the error string might be overwritten or deallocated by
4163** subsequent calls to other SQLite interface functions.)^
4164**
4165** ^The sqlite3_errstr(E) interface returns the English-language text
4166** that describes the [result code] E, as UTF-8, or NULL if E is not an
4167** result code for which a text error message is available.
4168** ^(Memory to hold the error message string is managed internally
4169** and must not be freed by the application)^.
4170**
4171** ^If the most recent error references a specific token in the input
4172** SQL, the sqlite3_error_offset() interface returns the byte offset
4173** of the start of that token. ^The byte offset returned by
4174** sqlite3_error_offset() assumes that the input SQL is UTF8.
4175** ^If the most recent error does not reference a specific token in the input
4176** SQL, then the sqlite3_error_offset() function returns -1.
4177**
4178** When the serialized [threading mode] is in use, it might be the
4179** case that a second error occurs on a separate thread in between
4180** the time of the first error and the call to these interfaces.
4181** When that happens, the second error will be reported since these
4182** interfaces always report the most recent result. To avoid
4183** this, each thread can obtain exclusive use of the [database connection] D
4184** by invoking [sqlite3_mutex_enter]([sqlite3_db_mutex](D)) before beginning
4185** to use D and invoking [sqlite3_mutex_leave]([sqlite3_db_mutex](D)) after
4186** all calls to the interfaces listed here are completed.
4187**
4188** If an interface fails with SQLITE_MISUSE, that means the interface
4189** was invoked incorrectly by the application. In that case, the
4190** error code and message may or may not be set.
4191*/
4192SQLITE_API int sqlite3_errcode(sqlite3 *db);
4193SQLITE_API int sqlite3_extended_errcode(sqlite3 *db);
4194SQLITE_API const char *sqlite3_errmsg(sqlite3*);
4195SQLITE_API const void *sqlite3_errmsg16(sqlite3*);
4196SQLITE_API const char *sqlite3_errstr(int);
4197SQLITE_API int sqlite3_error_offset(sqlite3 *db);
4198
4199/*
4200** CAPI3REF: Prepared Statement Object
4201** KEYWORDS: {prepared statement} {prepared statements}
4202**
4203** An instance of this object represents a single SQL statement that
4204** has been compiled into binary form and is ready to be evaluated.
4205**
4206** Think of each SQL statement as a separate computer program. The
4207** original SQL text is source code. A prepared statement object
4208** is the compiled object code. All SQL must be converted into a
4209** prepared statement before it can be run.
4210**
4211** The life-cycle of a prepared statement object usually goes like this:
4212**
4213** <ol>
4214** <li> Create the prepared statement object using [sqlite3_prepare_v2()].
4215** <li> Bind values to [parameters] using the sqlite3_bind_*()
4216** interfaces.
4217** <li> Run the SQL by calling [sqlite3_step()] one or more times.
4218** <li> Reset the prepared statement using [sqlite3_reset()] then go back
4219** to step 2. Do this zero or more times.
4220** <li> Destroy the object using [sqlite3_finalize()].
4221** </ol>
4222*/
4223typedef struct sqlite3_stmt sqlite3_stmt;
4224
4225/*
4226** CAPI3REF: Run-time Limits
4227** METHOD: sqlite3
4228**
4229** ^(This interface allows the size of various constructs to be limited
4230** on a connection by connection basis. The first parameter is the
4231** [database connection] whose limit is to be set or queried. The
4232** second parameter is one of the [limit categories] that define a
4233** class of constructs to be size limited. The third parameter is the
4234** new limit for that construct.)^
4235**
4236** ^If the new limit is a negative number, the limit is unchanged.
4237** ^(For each limit category SQLITE_LIMIT_<i>NAME</i> there is a
4238** [limits | hard upper bound]
4239** set at compile-time by a C preprocessor macro called
4240** [limits | SQLITE_MAX_<i>NAME</i>].
4241** (The "_LIMIT_" in the name is changed to "_MAX_".))^
4242** ^Attempts to increase a limit above its hard upper bound are
4243** silently truncated to the hard upper bound.
4244**
4245** ^Regardless of whether or not the limit was changed, the
4246** [sqlite3_limit()] interface returns the prior value of the limit.
4247** ^Hence, to find the current value of a limit without changing it,
4248** simply invoke this interface with the third parameter set to -1.
4249**
4250** Run-time limits are intended for use in applications that manage
4251** both their own internal database and also databases that are controlled
4252** by untrusted external sources. An example application might be a
4253** web browser that has its own databases for storing history and
4254** separate databases controlled by JavaScript applications downloaded
4255** off the Internet. The internal databases can be given the
4256** large, default limits. Databases managed by external sources can
4257** be given much smaller limits designed to prevent a denial of service
4258** attack. Developers might also want to use the [sqlite3_set_authorizer()]
4259** interface to further control untrusted SQL. The size of the database
4260** created by an untrusted script can be contained using the
4261** [max_page_count] [PRAGMA].
4262**
4263** New run-time limit categories may be added in future releases.
4264*/
4265SQLITE_API int sqlite3_limit(sqlite3*, int id, int newVal);
4266
4267/*
4268** CAPI3REF: Run-Time Limit Categories
4269** KEYWORDS: {limit category} {*limit categories}
4270**
4271** These constants define various performance limits
4272** that can be lowered at run-time using [sqlite3_limit()].
4273** The synopsis of the meanings of the various limits is shown below.
4274** Additional information is available at [limits | Limits in SQLite].
4275**
4276** <dl>
4277** [[SQLITE_LIMIT_LENGTH]] ^(<dt>SQLITE_LIMIT_LENGTH</dt>
4278** <dd>The maximum size of any string or BLOB or table row, in bytes.<dd>)^
4279**
4280** [[SQLITE_LIMIT_SQL_LENGTH]] ^(<dt>SQLITE_LIMIT_SQL_LENGTH</dt>
4281** <dd>The maximum length of an SQL statement, in bytes.</dd>)^
4282**
4283** [[SQLITE_LIMIT_COLUMN]] ^(<dt>SQLITE_LIMIT_COLUMN</dt>
4284** <dd>The maximum number of columns in a table definition or in the
4285** result set of a [SELECT] or the maximum number of columns in an index
4286** or in an ORDER BY or GROUP BY clause.</dd>)^
4287**
4288** [[SQLITE_LIMIT_EXPR_DEPTH]] ^(<dt>SQLITE_LIMIT_EXPR_DEPTH</dt>
4289** <dd>The maximum depth of the parse tree on any expression.</dd>)^
4290**
4291** [[SQLITE_LIMIT_COMPOUND_SELECT]] ^(<dt>SQLITE_LIMIT_COMPOUND_SELECT</dt>
4292** <dd>The maximum number of terms in a compound SELECT statement.</dd>)^
4293**
4294** [[SQLITE_LIMIT_VDBE_OP]] ^(<dt>SQLITE_LIMIT_VDBE_OP</dt>
4295** <dd>The maximum number of instructions in a virtual machine program
4296** used to implement an SQL statement. If [sqlite3_prepare_v2()] or
4297** the equivalent tries to allocate space for more than this many opcodes
4298** in a single prepared statement, an SQLITE_NOMEM error is returned.</dd>)^
4299**
4300** [[SQLITE_LIMIT_FUNCTION_ARG]] ^(<dt>SQLITE_LIMIT_FUNCTION_ARG</dt>
4301** <dd>The maximum number of arguments on a function.</dd>)^
4302**
4303** [[SQLITE_LIMIT_ATTACHED]] ^(<dt>SQLITE_LIMIT_ATTACHED</dt>
4304** <dd>The maximum number of [ATTACH | attached databases].)^</dd>
4305**
4306** [[SQLITE_LIMIT_LIKE_PATTERN_LENGTH]]
4307** ^(<dt>SQLITE_LIMIT_LIKE_PATTERN_LENGTH</dt>
4308** <dd>The maximum length of the pattern argument to the [LIKE] or
4309** [GLOB] operators.</dd>)^
4310**
4311** [[SQLITE_LIMIT_VARIABLE_NUMBER]]
4312** ^(<dt>SQLITE_LIMIT_VARIABLE_NUMBER</dt>
4313** <dd>The maximum index number of any [parameter] in an SQL statement.)^
4314**
4315** [[SQLITE_LIMIT_TRIGGER_DEPTH]] ^(<dt>SQLITE_LIMIT_TRIGGER_DEPTH</dt>
4316** <dd>The maximum depth of recursion for triggers.</dd>)^
4317**
4318** [[SQLITE_LIMIT_WORKER_THREADS]] ^(<dt>SQLITE_LIMIT_WORKER_THREADS</dt>
4319** <dd>The maximum number of auxiliary worker threads that a single
4320** [prepared statement] may start.</dd>)^
4321** </dl>
4322*/
4323#define SQLITE_LIMIT_LENGTH 0
4324#define SQLITE_LIMIT_SQL_LENGTH 1
4325#define SQLITE_LIMIT_COLUMN 2
4326#define SQLITE_LIMIT_EXPR_DEPTH 3
4327#define SQLITE_LIMIT_COMPOUND_SELECT 4
4328#define SQLITE_LIMIT_VDBE_OP 5
4329#define SQLITE_LIMIT_FUNCTION_ARG 6
4330#define SQLITE_LIMIT_ATTACHED 7
4331#define SQLITE_LIMIT_LIKE_PATTERN_LENGTH 8
4332#define SQLITE_LIMIT_VARIABLE_NUMBER 9
4333#define SQLITE_LIMIT_TRIGGER_DEPTH 10
4334#define SQLITE_LIMIT_WORKER_THREADS 11
4335
4336/*
4337** CAPI3REF: Prepare Flags
4338**
4339** These constants define various flags that can be passed into
4340** "prepFlags" parameter of the [sqlite3_prepare_v3()] and
4341** [sqlite3_prepare16_v3()] interfaces.
4342**
4343** New flags may be added in future releases of SQLite.
4344**
4345** <dl>
4346** [[SQLITE_PREPARE_PERSISTENT]] ^(<dt>SQLITE_PREPARE_PERSISTENT</dt>
4347** <dd>The SQLITE_PREPARE_PERSISTENT flag is a hint to the query planner
4348** that the prepared statement will be retained for a long time and
4349** probably reused many times.)^ ^Without this flag, [sqlite3_prepare_v3()]
4350** and [sqlite3_prepare16_v3()] assume that the prepared statement will
4351** be used just once or at most a few times and then destroyed using
4352** [sqlite3_finalize()] relatively soon. The current implementation acts
4353** on this hint by avoiding the use of [lookaside memory] so as not to
4354** deplete the limited store of lookaside memory. Future versions of
4355** SQLite may act on this hint differently.
4356**
4357** [[SQLITE_PREPARE_NORMALIZE]] <dt>SQLITE_PREPARE_NORMALIZE</dt>
4358** <dd>The SQLITE_PREPARE_NORMALIZE flag is a no-op. This flag used
4359** to be required for any prepared statement that wanted to use the
4360** [sqlite3_normalized_sql()] interface. However, the
4361** [sqlite3_normalized_sql()] interface is now available to all
4362** prepared statements, regardless of whether or not they use this
4363** flag.
4364**
4365** [[SQLITE_PREPARE_NO_VTAB]] <dt>SQLITE_PREPARE_NO_VTAB</dt>
4366** <dd>The SQLITE_PREPARE_NO_VTAB flag causes the SQL compiler
4367** to return an error (error code SQLITE_ERROR) if the statement uses
4368** any virtual tables.
4369**
4370** [[SQLITE_PREPARE_DONT_LOG]] <dt>SQLITE_PREPARE_DONT_LOG</dt>
4371** <dd>The SQLITE_PREPARE_DONT_LOG flag prevents SQL compiler
4372** errors from being sent to the error log defined by
4373** [SQLITE_CONFIG_LOG]. This can be used, for example, to do test
4374** compiles to see if some SQL syntax is well-formed, without generating
4375** messages on the global error log when it is not. If the test compile
4376** fails, the sqlite3_prepare_v3() call returns the same error indications
4377** with or without this flag; it just omits the call to [sqlite3_log()] that
4378** logs the error.
4379** </dl>
4380*/
4381#define SQLITE_PREPARE_PERSISTENT 0x01
4382#define SQLITE_PREPARE_NORMALIZE 0x02
4383#define SQLITE_PREPARE_NO_VTAB 0x04
4384#define SQLITE_PREPARE_DONT_LOG 0x10
4385
4386/*
4387** CAPI3REF: Compiling An SQL Statement
4388** KEYWORDS: {SQL statement compiler}
4389** METHOD: sqlite3
4390** CONSTRUCTOR: sqlite3_stmt
4391**
4392** To execute an SQL statement, it must first be compiled into a byte-code
4393** program using one of these routines. Or, in other words, these routines
4394** are constructors for the [prepared statement] object.
4395**
4396** The preferred routine to use is [sqlite3_prepare_v2()]. The
4397** [sqlite3_prepare()] interface is legacy and should be avoided.
4398** [sqlite3_prepare_v3()] has an extra "prepFlags" option that is used
4399** for special purposes.
4400**
4401** The use of the UTF-8 interfaces is preferred, as SQLite currently
4402** does all parsing using UTF-8. The UTF-16 interfaces are provided
4403** as a convenience. The UTF-16 interfaces work by converting the
4404** input text into UTF-8, then invoking the corresponding UTF-8 interface.
4405**
4406** The first argument, "db", is a [database connection] obtained from a
4407** prior successful call to [sqlite3_open()], [sqlite3_open_v2()] or
4408** [sqlite3_open16()]. The database connection must not have been closed.
4409**
4410** The second argument, "zSql", is the statement to be compiled, encoded
4411** as either UTF-8 or UTF-16. The sqlite3_prepare(), sqlite3_prepare_v2(),
4412** and sqlite3_prepare_v3()
4413** interfaces use UTF-8, and sqlite3_prepare16(), sqlite3_prepare16_v2(),
4414** and sqlite3_prepare16_v3() use UTF-16.
4415**
4416** ^If the nByte argument is negative, then zSql is read up to the
4417** first zero terminator. ^If nByte is positive, then it is the maximum
4418** number of bytes read from zSql. When nByte is positive, zSql is read
4419** up to the first zero terminator or until the nByte bytes have been read,
4420** whichever comes first. ^If nByte is zero, then no prepared
4421** statement is generated.
4422** If the caller knows that the supplied string is nul-terminated, then
4423** there is a small performance advantage to passing an nByte parameter that
4424** is the number of bytes in the input string <i>including</i>
4425** the nul-terminator.
4426** Note that nByte measure the length of the input in bytes, not
4427** characters, even for the UTF-16 interfaces.
4428**
4429** ^If pzTail is not NULL then *pzTail is made to point to the first byte
4430** past the end of the first SQL statement in zSql. These routines only
4431** compile the first statement in zSql, so *pzTail is left pointing to
4432** what remains uncompiled.
4433**
4434** ^*ppStmt is left pointing to a compiled [prepared statement] that can be
4435** executed using [sqlite3_step()]. ^If there is an error, *ppStmt is set
4436** to NULL. ^If the input text contains no SQL (if the input is an empty
4437** string or a comment) then *ppStmt is set to NULL.
4438** The calling procedure is responsible for deleting the compiled
4439** SQL statement using [sqlite3_finalize()] after it has finished with it.
4440** ppStmt may not be NULL.
4441**
4442** ^On success, the sqlite3_prepare() family of routines return [SQLITE_OK];
4443** otherwise an [error code] is returned.
4444**
4445** The sqlite3_prepare_v2(), sqlite3_prepare_v3(), sqlite3_prepare16_v2(),
4446** and sqlite3_prepare16_v3() interfaces are recommended for all new programs.
4447** The older interfaces (sqlite3_prepare() and sqlite3_prepare16())
4448** are retained for backwards compatibility, but their use is discouraged.
4449** ^In the "vX" interfaces, the prepared statement
4450** that is returned (the [sqlite3_stmt] object) contains a copy of the
4451** original SQL text. This causes the [sqlite3_step()] interface to
4452** behave differently in three ways:
4453**
4454** <ol>
4455** <li>
4456** ^If the database schema changes, instead of returning [SQLITE_SCHEMA] as it
4457** always used to do, [sqlite3_step()] will automatically recompile the SQL
4458** statement and try to run it again. As many as [SQLITE_MAX_SCHEMA_RETRY]
4459** retries will occur before sqlite3_step() gives up and returns an error.
4460** </li>
4461**
4462** <li>
4463** ^When an error occurs, [sqlite3_step()] will return one of the detailed
4464** [error codes] or [extended error codes]. ^The legacy behavior was that
4465** [sqlite3_step()] would only return a generic [SQLITE_ERROR] result code
4466** and the application would have to make a second call to [sqlite3_reset()]
4467** in order to find the underlying cause of the problem. With the "v2" prepare
4468** interfaces, the underlying reason for the error is returned immediately.
4469** </li>
4470**
4471** <li>
4472** ^If the specific value bound to a [parameter | host parameter] in the
4473** WHERE clause might influence the choice of query plan for a statement,
4474** then the statement will be automatically recompiled, as if there had been
4475** a schema change, on the first [sqlite3_step()] call following any change
4476** to the [sqlite3_bind_text | bindings] of that [parameter].
4477** ^The specific value of a WHERE-clause [parameter] might influence the
4478** choice of query plan if the parameter is the left-hand side of a [LIKE]
4479** or [GLOB] operator or if the parameter is compared to an indexed column
4480** and the [SQLITE_ENABLE_STAT4] compile-time option is enabled.
4481** </li>
4482** </ol>
4483**
4484** <p>^sqlite3_prepare_v3() differs from sqlite3_prepare_v2() only in having
4485** the extra prepFlags parameter, which is a bit array consisting of zero or
4486** more of the [SQLITE_PREPARE_PERSISTENT|SQLITE_PREPARE_*] flags. ^The
4487** sqlite3_prepare_v2() interface works exactly the same as
4488** sqlite3_prepare_v3() with a zero prepFlags parameter.
4489*/
4490SQLITE_API int sqlite3_prepare(
4491 sqlite3 *db, /* Database handle */
4492 const char *zSql, /* SQL statement, UTF-8 encoded */
4493 int nByte, /* Maximum length of zSql in bytes. */
4494 sqlite3_stmt **ppStmt, /* OUT: Statement handle */
4495 const char **pzTail /* OUT: Pointer to unused portion of zSql */
4496);
4497SQLITE_API int sqlite3_prepare_v2(
4498 sqlite3 *db, /* Database handle */
4499 const char *zSql, /* SQL statement, UTF-8 encoded */
4500 int nByte, /* Maximum length of zSql in bytes. */
4501 sqlite3_stmt **ppStmt, /* OUT: Statement handle */
4502 const char **pzTail /* OUT: Pointer to unused portion of zSql */
4503);
4504SQLITE_API int sqlite3_prepare_v3(
4505 sqlite3 *db, /* Database handle */
4506 const char *zSql, /* SQL statement, UTF-8 encoded */
4507 int nByte, /* Maximum length of zSql in bytes. */
4508 unsigned int prepFlags, /* Zero or more SQLITE_PREPARE_ flags */
4509 sqlite3_stmt **ppStmt, /* OUT: Statement handle */
4510 const char **pzTail /* OUT: Pointer to unused portion of zSql */
4511);
4512SQLITE_API int sqlite3_prepare16(
4513 sqlite3 *db, /* Database handle */
4514 const void *zSql, /* SQL statement, UTF-16 encoded */
4515 int nByte, /* Maximum length of zSql in bytes. */
4516 sqlite3_stmt **ppStmt, /* OUT: Statement handle */
4517 const void **pzTail /* OUT: Pointer to unused portion of zSql */
4518);
4519SQLITE_API int sqlite3_prepare16_v2(
4520 sqlite3 *db, /* Database handle */
4521 const void *zSql, /* SQL statement, UTF-16 encoded */
4522 int nByte, /* Maximum length of zSql in bytes. */
4523 sqlite3_stmt **ppStmt, /* OUT: Statement handle */
4524 const void **pzTail /* OUT: Pointer to unused portion of zSql */
4525);
4526SQLITE_API int sqlite3_prepare16_v3(
4527 sqlite3 *db, /* Database handle */
4528 const void *zSql, /* SQL statement, UTF-16 encoded */
4529 int nByte, /* Maximum length of zSql in bytes. */
4530 unsigned int prepFlags, /* Zero or more SQLITE_PREPARE_ flags */
4531 sqlite3_stmt **ppStmt, /* OUT: Statement handle */
4532 const void **pzTail /* OUT: Pointer to unused portion of zSql */
4533);
4534
4535/*
4536** CAPI3REF: Retrieving Statement SQL
4537** METHOD: sqlite3_stmt
4538**
4539** ^The sqlite3_sql(P) interface returns a pointer to a copy of the UTF-8
4540** SQL text used to create [prepared statement] P if P was
4541** created by [sqlite3_prepare_v2()], [sqlite3_prepare_v3()],
4542** [sqlite3_prepare16_v2()], or [sqlite3_prepare16_v3()].
4543** ^The sqlite3_expanded_sql(P) interface returns a pointer to a UTF-8
4544** string containing the SQL text of prepared statement P with
4545** [bound parameters] expanded.
4546** ^The sqlite3_normalized_sql(P) interface returns a pointer to a UTF-8
4547** string containing the normalized SQL text of prepared statement P. The
4548** semantics used to normalize a SQL statement are unspecified and subject
4549** to change. At a minimum, literal values will be replaced with suitable
4550** placeholders.
4551**
4552** ^(For example, if a prepared statement is created using the SQL
4553** text "SELECT $abc,:xyz" and if parameter $abc is bound to integer 2345
4554** and parameter :xyz is unbound, then sqlite3_sql() will return
4555** the original string, "SELECT $abc,:xyz" but sqlite3_expanded_sql()
4556** will return "SELECT 2345,NULL".)^
4557**
4558** ^The sqlite3_expanded_sql() interface returns NULL if insufficient memory
4559** is available to hold the result, or if the result would exceed the
4560** the maximum string length determined by the [SQLITE_LIMIT_LENGTH].
4561**
4562** ^The [SQLITE_TRACE_SIZE_LIMIT] compile-time option limits the size of
4563** bound parameter expansions. ^The [SQLITE_OMIT_TRACE] compile-time
4564** option causes sqlite3_expanded_sql() to always return NULL.
4565**
4566** ^The strings returned by sqlite3_sql(P) and sqlite3_normalized_sql(P)
4567** are managed by SQLite and are automatically freed when the prepared
4568** statement is finalized.
4569** ^The string returned by sqlite3_expanded_sql(P), on the other hand,
4570** is obtained from [sqlite3_malloc()] and must be freed by the application
4571** by passing it to [sqlite3_free()].
4572**
4573** ^The sqlite3_normalized_sql() interface is only available if
4574** the [SQLITE_ENABLE_NORMALIZE] compile-time option is defined.
4575*/
4576SQLITE_API const char *sqlite3_sql(sqlite3_stmt *pStmt);
4577SQLITE_API char *sqlite3_expanded_sql(sqlite3_stmt *pStmt);
4578#ifdef SQLITE_ENABLE_NORMALIZE
4579SQLITE_API const char *sqlite3_normalized_sql(sqlite3_stmt *pStmt);
4580#endif
4581
4582/*
4583** CAPI3REF: Determine If An SQL Statement Writes The Database
4584** METHOD: sqlite3_stmt
4585**
4586** ^The sqlite3_stmt_readonly(X) interface returns true (non-zero) if
4587** and only if the [prepared statement] X makes no direct changes to
4588** the content of the database file.
4589**
4590** Note that [application-defined SQL functions] or
4591** [virtual tables] might change the database indirectly as a side effect.
4592** ^(For example, if an application defines a function "eval()" that
4593** calls [sqlite3_exec()], then the following SQL statement would
4594** change the database file through side-effects:
4595**
4596** <blockquote><pre>
4597** SELECT eval('DELETE FROM t1') FROM t2;
4598** </pre></blockquote>
4599**
4600** But because the [SELECT] statement does not change the database file
4601** directly, sqlite3_stmt_readonly() would still return true.)^
4602**
4603** ^Transaction control statements such as [BEGIN], [COMMIT], [ROLLBACK],
4604** [SAVEPOINT], and [RELEASE] cause sqlite3_stmt_readonly() to return true,
4605** since the statements themselves do not actually modify the database but
4606** rather they control the timing of when other statements modify the
4607** database. ^The [ATTACH] and [DETACH] statements also cause
4608** sqlite3_stmt_readonly() to return true since, while those statements
4609** change the configuration of a database connection, they do not make
4610** changes to the content of the database files on disk.
4611** ^The sqlite3_stmt_readonly() interface returns true for [BEGIN] since
4612** [BEGIN] merely sets internal flags, but the [BEGIN|BEGIN IMMEDIATE] and
4613** [BEGIN|BEGIN EXCLUSIVE] commands do touch the database and so
4614** sqlite3_stmt_readonly() returns false for those commands.
4615**
4616** ^This routine returns false if there is any possibility that the
4617** statement might change the database file. ^A false return does
4618** not guarantee that the statement will change the database file.
4619** ^For example, an UPDATE statement might have a WHERE clause that
4620** makes it a no-op, but the sqlite3_stmt_readonly() result would still
4621** be false. ^Similarly, a CREATE TABLE IF NOT EXISTS statement is a
4622** read-only no-op if the table already exists, but
4623** sqlite3_stmt_readonly() still returns false for such a statement.
4624**
4625** ^If prepared statement X is an [EXPLAIN] or [EXPLAIN QUERY PLAN]
4626** statement, then sqlite3_stmt_readonly(X) returns the same value as
4627** if the EXPLAIN or EXPLAIN QUERY PLAN prefix were omitted.
4628*/
4629SQLITE_API int sqlite3_stmt_readonly(sqlite3_stmt *pStmt);
4630
4631/*
4632** CAPI3REF: Query The EXPLAIN Setting For A Prepared Statement
4633** METHOD: sqlite3_stmt
4634**
4635** ^The sqlite3_stmt_isexplain(S) interface returns 1 if the
4636** prepared statement S is an EXPLAIN statement, or 2 if the
4637** statement S is an EXPLAIN QUERY PLAN.
4638** ^The sqlite3_stmt_isexplain(S) interface returns 0 if S is
4639** an ordinary statement or a NULL pointer.
4640*/
4641SQLITE_API int sqlite3_stmt_isexplain(sqlite3_stmt *pStmt);
4642
4643/*
4644** CAPI3REF: Change The EXPLAIN Setting For A Prepared Statement
4645** METHOD: sqlite3_stmt
4646**
4647** The sqlite3_stmt_explain(S,E) interface changes the EXPLAIN
4648** setting for [prepared statement] S. If E is zero, then S becomes
4649** a normal prepared statement. If E is 1, then S behaves as if
4650** its SQL text began with "[EXPLAIN]". If E is 2, then S behaves as if
4651** its SQL text began with "[EXPLAIN QUERY PLAN]".
4652**
4653** Calling sqlite3_stmt_explain(S,E) might cause S to be reprepared.
4654** SQLite tries to avoid a reprepare, but a reprepare might be necessary
4655** on the first transition into EXPLAIN or EXPLAIN QUERY PLAN mode.
4656**
4657** Because of the potential need to reprepare, a call to
4658** sqlite3_stmt_explain(S,E) will fail with SQLITE_ERROR if S cannot be
4659** reprepared because it was created using [sqlite3_prepare()] instead of
4660** the newer [sqlite3_prepare_v2()] or [sqlite3_prepare_v3()] interfaces and
4661** hence has no saved SQL text with which to reprepare.
4662**
4663** Changing the explain setting for a prepared statement does not change
4664** the original SQL text for the statement. Hence, if the SQL text originally
4665** began with EXPLAIN or EXPLAIN QUERY PLAN, but sqlite3_stmt_explain(S,0)
4666** is called to convert the statement into an ordinary statement, the EXPLAIN
4667** or EXPLAIN QUERY PLAN keywords will still appear in the sqlite3_sql(S)
4668** output, even though the statement now acts like a normal SQL statement.
4669**
4670** This routine returns SQLITE_OK if the explain mode is successfully
4671** changed, or an error code if the explain mode could not be changed.
4672** The explain mode cannot be changed while a statement is active.
4673** Hence, it is good practice to call [sqlite3_reset(S)]
4674** immediately prior to calling sqlite3_stmt_explain(S,E).
4675*/
4676SQLITE_API int sqlite3_stmt_explain(sqlite3_stmt *pStmt, int eMode);
4677
4678/*
4679** CAPI3REF: Determine If A Prepared Statement Has Been Reset
4680** METHOD: sqlite3_stmt
4681**
4682** ^The sqlite3_stmt_busy(S) interface returns true (non-zero) if the
4683** [prepared statement] S has been stepped at least once using
4684** [sqlite3_step(S)] but has neither run to completion (returned
4685** [SQLITE_DONE] from [sqlite3_step(S)]) nor
4686** been reset using [sqlite3_reset(S)]. ^The sqlite3_stmt_busy(S)
4687** interface returns false if S is a NULL pointer. If S is not a
4688** NULL pointer and is not a pointer to a valid [prepared statement]
4689** object, then the behavior is undefined and probably undesirable.
4690**
4691** This interface can be used in combination [sqlite3_next_stmt()]
4692** to locate all prepared statements associated with a database
4693** connection that are in need of being reset. This can be used,
4694** for example, in diagnostic routines to search for prepared
4695** statements that are holding a transaction open.
4696*/
4697SQLITE_API int sqlite3_stmt_busy(sqlite3_stmt*);
4698
4699/*
4700** CAPI3REF: Dynamically Typed Value Object
4701** KEYWORDS: {protected sqlite3_value} {unprotected sqlite3_value}
4702**
4703** SQLite uses the sqlite3_value object to represent all values
4704** that can be stored in a database table. SQLite uses dynamic typing
4705** for the values it stores. ^Values stored in sqlite3_value objects
4706** can be integers, floating point values, strings, BLOBs, or NULL.
4707**
4708** An sqlite3_value object may be either "protected" or "unprotected".
4709** Some interfaces require a protected sqlite3_value. Other interfaces
4710** will accept either a protected or an unprotected sqlite3_value.
4711** Every interface that accepts sqlite3_value arguments specifies
4712** whether or not it requires a protected sqlite3_value. The
4713** [sqlite3_value_dup()] interface can be used to construct a new
4714** protected sqlite3_value from an unprotected sqlite3_value.
4715**
4716** The terms "protected" and "unprotected" refer to whether or not
4717** a mutex is held. An internal mutex is held for a protected
4718** sqlite3_value object but no mutex is held for an unprotected
4719** sqlite3_value object. If SQLite is compiled to be single-threaded
4720** (with [SQLITE_THREADSAFE=0] and with [sqlite3_threadsafe()] returning 0)
4721** or if SQLite is run in one of reduced mutex modes
4722** [SQLITE_CONFIG_SINGLETHREAD] or [SQLITE_CONFIG_MULTITHREAD]
4723** then there is no distinction between protected and unprotected
4724** sqlite3_value objects and they can be used interchangeably. However,
4725** for maximum code portability it is recommended that applications
4726** still make the distinction between protected and unprotected
4727** sqlite3_value objects even when not strictly required.
4728**
4729** ^The sqlite3_value objects that are passed as parameters into the
4730** implementation of [application-defined SQL functions] are protected.
4731** ^The sqlite3_value objects returned by [sqlite3_vtab_rhs_value()]
4732** are protected.
4733** ^The sqlite3_value object returned by
4734** [sqlite3_column_value()] is unprotected.
4735** Unprotected sqlite3_value objects may only be used as arguments
4736** to [sqlite3_result_value()], [sqlite3_bind_value()], and
4737** [sqlite3_value_dup()].
4738** The [sqlite3_value_blob | sqlite3_value_type()] family of
4739** interfaces require protected sqlite3_value objects.
4740*/
4741typedef struct sqlite3_value sqlite3_value;
4742
4743/*
4744** CAPI3REF: SQL Function Context Object
4745**
4746** The context in which an SQL function executes is stored in an
4747** sqlite3_context object. ^A pointer to an sqlite3_context object
4748** is always first parameter to [application-defined SQL functions].
4749** The application-defined SQL function implementation will pass this
4750** pointer through into calls to [sqlite3_result_int | sqlite3_result()],
4751** [sqlite3_aggregate_context()], [sqlite3_user_data()],
4752** [sqlite3_context_db_handle()], [sqlite3_get_auxdata()],
4753** and/or [sqlite3_set_auxdata()].
4754*/
4755typedef struct sqlite3_context sqlite3_context;
4756
4757/*
4758** CAPI3REF: Binding Values To Prepared Statements
4759** KEYWORDS: {host parameter} {host parameters} {host parameter name}
4760** KEYWORDS: {SQL parameter} {SQL parameters} {parameter binding}
4761** METHOD: sqlite3_stmt
4762**
4763** ^(In the SQL statement text input to [sqlite3_prepare_v2()] and its variants,
4764** literals may be replaced by a [parameter] that matches one of the following
4765** templates:
4766**
4767** <ul>
4768** <li> ?
4769** <li> ?NNN
4770** <li> :VVV
4771** <li> @VVV
4772** <li> $VVV
4773** </ul>
4774**
4775** In the templates above, NNN represents an integer literal,
4776** and VVV represents an alphanumeric identifier.)^ ^The values of these
4777** parameters (also called "host parameter names" or "SQL parameters")
4778** can be set using the sqlite3_bind_*() routines defined here.
4779**
4780** ^The first argument to the sqlite3_bind_*() routines is always
4781** a pointer to the [sqlite3_stmt] object returned from
4782** [sqlite3_prepare_v2()] or its variants.
4783**
4784** ^The second argument is the index of the SQL parameter to be set.
4785** ^The leftmost SQL parameter has an index of 1. ^When the same named
4786** SQL parameter is used more than once, second and subsequent
4787** occurrences have the same index as the first occurrence.
4788** ^The index for named parameters can be looked up using the
4789** [sqlite3_bind_parameter_index()] API if desired. ^The index
4790** for "?NNN" parameters is the value of NNN.
4791** ^The NNN value must be between 1 and the [sqlite3_limit()]
4792** parameter [SQLITE_LIMIT_VARIABLE_NUMBER] (default value: 32766).
4793**
4794** ^The third argument is the value to bind to the parameter.
4795** ^If the third parameter to sqlite3_bind_text() or sqlite3_bind_text16()
4796** or sqlite3_bind_blob() is a NULL pointer then the fourth parameter
4797** is ignored and the end result is the same as sqlite3_bind_null().
4798** ^If the third parameter to sqlite3_bind_text() is not NULL, then
4799** it should be a pointer to well-formed UTF8 text.
4800** ^If the third parameter to sqlite3_bind_text16() is not NULL, then
4801** it should be a pointer to well-formed UTF16 text.
4802** ^If the third parameter to sqlite3_bind_text64() is not NULL, then
4803** it should be a pointer to a well-formed unicode string that is
4804** either UTF8 if the sixth parameter is SQLITE_UTF8, or UTF16
4805** otherwise.
4806**
4807** [[byte-order determination rules]] ^The byte-order of
4808** UTF16 input text is determined by the byte-order mark (BOM, U+FEFF)
4809** found in the first character, which is removed, or in the absence of a BOM
4810** the byte order is the native byte order of the host
4811** machine for sqlite3_bind_text16() or the byte order specified in
4812** the 6th parameter for sqlite3_bind_text64().)^
4813** ^If UTF16 input text contains invalid unicode
4814** characters, then SQLite might change those invalid characters
4815** into the unicode replacement character: U+FFFD.
4816**
4817** ^(In those routines that have a fourth argument, its value is the
4818** number of bytes in the parameter. To be clear: the value is the
4819** number of <u>bytes</u> in the value, not the number of characters.)^
4820** ^If the fourth parameter to sqlite3_bind_text() or sqlite3_bind_text16()
4821** is negative, then the length of the string is
4822** the number of bytes up to the first zero terminator.
4823** If the fourth parameter to sqlite3_bind_blob() is negative, then
4824** the behavior is undefined.
4825** If a non-negative fourth parameter is provided to sqlite3_bind_text()
4826** or sqlite3_bind_text16() or sqlite3_bind_text64() then
4827** that parameter must be the byte offset
4828** where the NUL terminator would occur assuming the string were NUL
4829** terminated. If any NUL characters occur at byte offsets less than
4830** the value of the fourth parameter then the resulting string value will
4831** contain embedded NULs. The result of expressions involving strings
4832** with embedded NULs is undefined.
4833**
4834** ^The fifth argument to the BLOB and string binding interfaces controls
4835** or indicates the lifetime of the object referenced by the third parameter.
4836** These three options exist:
4837** ^ (1) A destructor to dispose of the BLOB or string after SQLite has finished
4838** with it may be passed. ^It is called to dispose of the BLOB or string even
4839** if the call to the bind API fails, except the destructor is not called if
4840** the third parameter is a NULL pointer or the fourth parameter is negative.
4841** ^ (2) The special constant, [SQLITE_STATIC], may be passed to indicate that
4842** the application remains responsible for disposing of the object. ^In this
4843** case, the object and the provided pointer to it must remain valid until
4844** either the prepared statement is finalized or the same SQL parameter is
4845** bound to something else, whichever occurs sooner.
4846** ^ (3) The constant, [SQLITE_TRANSIENT], may be passed to indicate that the
4847** object is to be copied prior to the return from sqlite3_bind_*(). ^The
4848** object and pointer to it must remain valid until then. ^SQLite will then
4849** manage the lifetime of its private copy.
4850**
4851** ^The sixth argument to sqlite3_bind_text64() must be one of
4852** [SQLITE_UTF8], [SQLITE_UTF16], [SQLITE_UTF16BE], or [SQLITE_UTF16LE]
4853** to specify the encoding of the text in the third parameter. If
4854** the sixth argument to sqlite3_bind_text64() is not one of the
4855** allowed values shown above, or if the text encoding is different
4856** from the encoding specified by the sixth parameter, then the behavior
4857** is undefined.
4858**
4859** ^The sqlite3_bind_zeroblob() routine binds a BLOB of length N that
4860** is filled with zeroes. ^A zeroblob uses a fixed amount of memory
4861** (just an integer to hold its size) while it is being processed.
4862** Zeroblobs are intended to serve as placeholders for BLOBs whose
4863** content is later written using
4864** [sqlite3_blob_open | incremental BLOB I/O] routines.
4865** ^A negative value for the zeroblob results in a zero-length BLOB.
4866**
4867** ^The sqlite3_bind_pointer(S,I,P,T,D) routine causes the I-th parameter in
4868** [prepared statement] S to have an SQL value of NULL, but to also be
4869** associated with the pointer P of type T. ^D is either a NULL pointer or
4870** a pointer to a destructor function for P. ^SQLite will invoke the
4871** destructor D with a single argument of P when it is finished using
4872** P. The T parameter should be a static string, preferably a string
4873** literal. The sqlite3_bind_pointer() routine is part of the
4874** [pointer passing interface] added for SQLite 3.20.0.
4875**
4876** ^If any of the sqlite3_bind_*() routines are called with a NULL pointer
4877** for the [prepared statement] or with a prepared statement for which
4878** [sqlite3_step()] has been called more recently than [sqlite3_reset()],
4879** then the call will return [SQLITE_MISUSE]. If any sqlite3_bind_()
4880** routine is passed a [prepared statement] that has been finalized, the
4881** result is undefined and probably harmful.
4882**
4883** ^Bindings are not cleared by the [sqlite3_reset()] routine.
4884** ^Unbound parameters are interpreted as NULL.
4885**
4886** ^The sqlite3_bind_* routines return [SQLITE_OK] on success or an
4887** [error code] if anything goes wrong.
4888** ^[SQLITE_TOOBIG] might be returned if the size of a string or BLOB
4889** exceeds limits imposed by [sqlite3_limit]([SQLITE_LIMIT_LENGTH]) or
4890** [SQLITE_MAX_LENGTH].
4891** ^[SQLITE_RANGE] is returned if the parameter
4892** index is out of range. ^[SQLITE_NOMEM] is returned if malloc() fails.
4893**
4894** See also: [sqlite3_bind_parameter_count()],
4895** [sqlite3_bind_parameter_name()], and [sqlite3_bind_parameter_index()].
4896*/
4897SQLITE_API int sqlite3_bind_blob(sqlite3_stmt*, int, const void*, int n, void(*)(void*));
4898SQLITE_API int sqlite3_bind_blob64(sqlite3_stmt*, int, const void*, sqlite3_uint64,
4899 void(*)(void*));
4900SQLITE_API int sqlite3_bind_double(sqlite3_stmt*, int, double);
4901SQLITE_API int sqlite3_bind_int(sqlite3_stmt*, int, int);
4902SQLITE_API int sqlite3_bind_int64(sqlite3_stmt*, int, sqlite3_int64);
4903SQLITE_API int sqlite3_bind_null(sqlite3_stmt*, int);
4904SQLITE_API int sqlite3_bind_text(sqlite3_stmt*,int,const char*,int,void(*)(void*));
4905SQLITE_API int sqlite3_bind_text16(sqlite3_stmt*, int, const void*, int, void(*)(void*));
4906SQLITE_API int sqlite3_bind_text64(sqlite3_stmt*, int, const char*, sqlite3_uint64,
4907 void(*)(void*), unsigned char encoding);
4908SQLITE_API int sqlite3_bind_value(sqlite3_stmt*, int, const sqlite3_value*);
4909SQLITE_API int sqlite3_bind_pointer(sqlite3_stmt*, int, void*, const char*,void(*)(void*));
4910SQLITE_API int sqlite3_bind_zeroblob(sqlite3_stmt*, int, int n);
4911SQLITE_API int sqlite3_bind_zeroblob64(sqlite3_stmt*, int, sqlite3_uint64);
4912
4913/*
4914** CAPI3REF: Number Of SQL Parameters
4915** METHOD: sqlite3_stmt
4916**
4917** ^This routine can be used to find the number of [SQL parameters]
4918** in a [prepared statement]. SQL parameters are tokens of the
4919** form "?", "?NNN", ":AAA", "$AAA", or "@AAA" that serve as
4920** placeholders for values that are [sqlite3_bind_blob | bound]
4921** to the parameters at a later time.
4922**
4923** ^(This routine actually returns the index of the largest (rightmost)
4924** parameter. For all forms except ?NNN, this will correspond to the
4925** number of unique parameters. If parameters of the ?NNN form are used,
4926** there may be gaps in the list.)^
4927**
4928** See also: [sqlite3_bind_blob|sqlite3_bind()],
4929** [sqlite3_bind_parameter_name()], and
4930** [sqlite3_bind_parameter_index()].
4931*/
4932SQLITE_API int sqlite3_bind_parameter_count(sqlite3_stmt*);
4933
4934/*
4935** CAPI3REF: Name Of A Host Parameter
4936** METHOD: sqlite3_stmt
4937**
4938** ^The sqlite3_bind_parameter_name(P,N) interface returns
4939** the name of the N-th [SQL parameter] in the [prepared statement] P.
4940** ^(SQL parameters of the form "?NNN" or ":AAA" or "@AAA" or "$AAA"
4941** have a name which is the string "?NNN" or ":AAA" or "@AAA" or "$AAA"
4942** respectively.
4943** In other words, the initial ":" or "$" or "@" or "?"
4944** is included as part of the name.)^
4945** ^Parameters of the form "?" without a following integer have no name
4946** and are referred to as "nameless" or "anonymous parameters".
4947**
4948** ^The first host parameter has an index of 1, not 0.
4949**
4950** ^If the value N is out of range or if the N-th parameter is
4951** nameless, then NULL is returned. ^The returned string is
4952** always in UTF-8 encoding even if the named parameter was
4953** originally specified as UTF-16 in [sqlite3_prepare16()],
4954** [sqlite3_prepare16_v2()], or [sqlite3_prepare16_v3()].
4955**
4956** See also: [sqlite3_bind_blob|sqlite3_bind()],
4957** [sqlite3_bind_parameter_count()], and
4958** [sqlite3_bind_parameter_index()].
4959*/
4960SQLITE_API const char *sqlite3_bind_parameter_name(sqlite3_stmt*, int);
4961
4962/*
4963** CAPI3REF: Index Of A Parameter With A Given Name
4964** METHOD: sqlite3_stmt
4965**
4966** ^Return the index of an SQL parameter given its name. ^The
4967** index value returned is suitable for use as the second
4968** parameter to [sqlite3_bind_blob|sqlite3_bind()]. ^A zero
4969** is returned if no matching parameter is found. ^The parameter
4970** name must be given in UTF-8 even if the original statement
4971** was prepared from UTF-16 text using [sqlite3_prepare16_v2()] or
4972** [sqlite3_prepare16_v3()].
4973**
4974** See also: [sqlite3_bind_blob|sqlite3_bind()],
4975** [sqlite3_bind_parameter_count()], and
4976** [sqlite3_bind_parameter_name()].
4977*/
4978SQLITE_API int sqlite3_bind_parameter_index(sqlite3_stmt*, const char *zName);
4979
4980/*
4981** CAPI3REF: Reset All Bindings On A Prepared Statement
4982** METHOD: sqlite3_stmt
4983**
4984** ^Contrary to the intuition of many, [sqlite3_reset()] does not reset
4985** the [sqlite3_bind_blob | bindings] on a [prepared statement].
4986** ^Use this routine to reset all host parameters to NULL.
4987*/
4988SQLITE_API int sqlite3_clear_bindings(sqlite3_stmt*);
4989
4990/*
4991** CAPI3REF: Number Of Columns In A Result Set
4992** METHOD: sqlite3_stmt
4993**
4994** ^Return the number of columns in the result set returned by the
4995** [prepared statement]. ^If this routine returns 0, that means the
4996** [prepared statement] returns no data (for example an [UPDATE]).
4997** ^However, just because this routine returns a positive number does not
4998** mean that one or more rows of data will be returned. ^A SELECT statement
4999** will always have a positive sqlite3_column_count() but depending on the
5000** WHERE clause constraints and the table content, it might return no rows.
5001**
5002** See also: [sqlite3_data_count()]
5003*/
5004SQLITE_API int sqlite3_column_count(sqlite3_stmt *pStmt);
5005
5006/*
5007** CAPI3REF: Column Names In A Result Set
5008** METHOD: sqlite3_stmt
5009**
5010** ^These routines return the name assigned to a particular column
5011** in the result set of a [SELECT] statement. ^The sqlite3_column_name()
5012** interface returns a pointer to a zero-terminated UTF-8 string
5013** and sqlite3_column_name16() returns a pointer to a zero-terminated
5014** UTF-16 string. ^The first parameter is the [prepared statement]
5015** that implements the [SELECT] statement. ^The second parameter is the
5016** column number. ^The leftmost column is number 0.
5017**
5018** ^The returned string pointer is valid until either the [prepared statement]
5019** is destroyed by [sqlite3_finalize()] or until the statement is automatically
5020** reprepared by the first call to [sqlite3_step()] for a particular run
5021** or until the next call to
5022** sqlite3_column_name() or sqlite3_column_name16() on the same column.
5023**
5024** ^If sqlite3_malloc() fails during the processing of either routine
5025** (for example during a conversion from UTF-8 to UTF-16) then a
5026** NULL pointer is returned.
5027**
5028** ^The name of a result column is the value of the "AS" clause for
5029** that column, if there is an AS clause. If there is no AS clause
5030** then the name of the column is unspecified and may change from
5031** one release of SQLite to the next.
5032*/
5033SQLITE_API const char *sqlite3_column_name(sqlite3_stmt*, int N);
5034SQLITE_API const void *sqlite3_column_name16(sqlite3_stmt*, int N);
5035
5036/*
5037** CAPI3REF: Source Of Data In A Query Result
5038** METHOD: sqlite3_stmt
5039**
5040** ^These routines provide a means to determine the database, table, and
5041** table column that is the origin of a particular result column in a
5042** [SELECT] statement.
5043** ^The name of the database or table or column can be returned as
5044** either a UTF-8 or UTF-16 string. ^The _database_ routines return
5045** the database name, the _table_ routines return the table name, and
5046** the origin_ routines return the column name.
5047** ^The returned string is valid until the [prepared statement] is destroyed
5048** using [sqlite3_finalize()] or until the statement is automatically
5049** reprepared by the first call to [sqlite3_step()] for a particular run
5050** or until the same information is requested
5051** again in a different encoding.
5052**
5053** ^The names returned are the original un-aliased names of the
5054** database, table, and column.
5055**
5056** ^The first argument to these interfaces is a [prepared statement].
5057** ^These functions return information about the Nth result column returned by
5058** the statement, where N is the second function argument.
5059** ^The left-most column is column 0 for these routines.
5060**
5061** ^If the Nth column returned by the statement is an expression or
5062** subquery and is not a column value, then all of these functions return
5063** NULL. ^These routines might also return NULL if a memory allocation error
5064** occurs. ^Otherwise, they return the name of the attached database, table,
5065** or column that query result column was extracted from.
5066**
5067** ^As with all other SQLite APIs, those whose names end with "16" return
5068** UTF-16 encoded strings and the other functions return UTF-8.
5069**
5070** ^These APIs are only available if the library was compiled with the
5071** [SQLITE_ENABLE_COLUMN_METADATA] C-preprocessor symbol.
5072**
5073** If two or more threads call one or more
5074** [sqlite3_column_database_name | column metadata interfaces]
5075** for the same [prepared statement] and result column
5076** at the same time then the results are undefined.
5077*/
5078SQLITE_API const char *sqlite3_column_database_name(sqlite3_stmt*,int);
5079SQLITE_API const void *sqlite3_column_database_name16(sqlite3_stmt*,int);
5080SQLITE_API const char *sqlite3_column_table_name(sqlite3_stmt*,int);
5081SQLITE_API const void *sqlite3_column_table_name16(sqlite3_stmt*,int);
5082SQLITE_API const char *sqlite3_column_origin_name(sqlite3_stmt*,int);
5083SQLITE_API const void *sqlite3_column_origin_name16(sqlite3_stmt*,int);
5084
5085/*
5086** CAPI3REF: Declared Datatype Of A Query Result
5087** METHOD: sqlite3_stmt
5088**
5089** ^(The first parameter is a [prepared statement].
5090** If this statement is a [SELECT] statement and the Nth column of the
5091** returned result set of that [SELECT] is a table column (not an
5092** expression or subquery) then the declared type of the table
5093** column is returned.)^ ^If the Nth column of the result set is an
5094** expression or subquery, then a NULL pointer is returned.
5095** ^The returned string is always UTF-8 encoded.
5096**
5097** ^(For example, given the database schema:
5098**
5099** CREATE TABLE t1(c1 VARIANT);
5100**
5101** and the following statement to be compiled:
5102**
5103** SELECT c1 + 1, c1 FROM t1;
5104**
5105** this routine would return the string "VARIANT" for the second result
5106** column (i==1), and a NULL pointer for the first result column (i==0).)^
5107**
5108** ^SQLite uses dynamic run-time typing. ^So just because a column
5109** is declared to contain a particular type does not mean that the
5110** data stored in that column is of the declared type. SQLite is
5111** strongly typed, but the typing is dynamic not static. ^Type
5112** is associated with individual values, not with the containers
5113** used to hold those values.
5114*/
5115SQLITE_API const char *sqlite3_column_decltype(sqlite3_stmt*,int);
5116SQLITE_API const void *sqlite3_column_decltype16(sqlite3_stmt*,int);
5117
5118/*
5119** CAPI3REF: Evaluate An SQL Statement
5120** METHOD: sqlite3_stmt
5121**
5122** After a [prepared statement] has been prepared using any of
5123** [sqlite3_prepare_v2()], [sqlite3_prepare_v3()], [sqlite3_prepare16_v2()],
5124** or [sqlite3_prepare16_v3()] or one of the legacy
5125** interfaces [sqlite3_prepare()] or [sqlite3_prepare16()], this function
5126** must be called one or more times to evaluate the statement.
5127**
5128** The details of the behavior of the sqlite3_step() interface depend
5129** on whether the statement was prepared using the newer "vX" interfaces
5130** [sqlite3_prepare_v3()], [sqlite3_prepare_v2()], [sqlite3_prepare16_v3()],
5131** [sqlite3_prepare16_v2()] or the older legacy
5132** interfaces [sqlite3_prepare()] and [sqlite3_prepare16()]. The use of the
5133** new "vX" interface is recommended for new applications but the legacy
5134** interface will continue to be supported.
5135**
5136** ^In the legacy interface, the return value will be either [SQLITE_BUSY],
5137** [SQLITE_DONE], [SQLITE_ROW], [SQLITE_ERROR], or [SQLITE_MISUSE].
5138** ^With the "v2" interface, any of the other [result codes] or
5139** [extended result codes] might be returned as well.
5140**
5141** ^[SQLITE_BUSY] means that the database engine was unable to acquire the
5142** database locks it needs to do its job. ^If the statement is a [COMMIT]
5143** or occurs outside of an explicit transaction, then you can retry the
5144** statement. If the statement is not a [COMMIT] and occurs within an
5145** explicit transaction then you should rollback the transaction before
5146** continuing.
5147**
5148** ^[SQLITE_DONE] means that the statement has finished executing
5149** successfully. sqlite3_step() should not be called again on this virtual
5150** machine without first calling [sqlite3_reset()] to reset the virtual
5151** machine back to its initial state.
5152**
5153** ^If the SQL statement being executed returns any data, then [SQLITE_ROW]
5154** is returned each time a new row of data is ready for processing by the
5155** caller. The values may be accessed using the [column access functions].
5156** sqlite3_step() is called again to retrieve the next row of data.
5157**
5158** ^[SQLITE_ERROR] means that a run-time error (such as a constraint
5159** violation) has occurred. sqlite3_step() should not be called again on
5160** the VM. More information may be found by calling [sqlite3_errmsg()].
5161** ^With the legacy interface, a more specific error code (for example,
5162** [SQLITE_INTERRUPT], [SQLITE_SCHEMA], [SQLITE_CORRUPT], and so forth)
5163** can be obtained by calling [sqlite3_reset()] on the
5164** [prepared statement]. ^In the "v2" interface,
5165** the more specific error code is returned directly by sqlite3_step().
5166**
5167** [SQLITE_MISUSE] means that the this routine was called inappropriately.
5168** Perhaps it was called on a [prepared statement] that has
5169** already been [sqlite3_finalize | finalized] or on one that had
5170** previously returned [SQLITE_ERROR] or [SQLITE_DONE]. Or it could
5171** be the case that the same database connection is being used by two or
5172** more threads at the same moment in time.
5173**
5174** For all versions of SQLite up to and including 3.6.23.1, a call to
5175** [sqlite3_reset()] was required after sqlite3_step() returned anything
5176** other than [SQLITE_ROW] before any subsequent invocation of
5177** sqlite3_step(). Failure to reset the prepared statement using
5178** [sqlite3_reset()] would result in an [SQLITE_MISUSE] return from
5179** sqlite3_step(). But after [version 3.6.23.1] ([dateof:3.6.23.1]),
5180** sqlite3_step() began
5181** calling [sqlite3_reset()] automatically in this circumstance rather
5182** than returning [SQLITE_MISUSE]. This is not considered a compatibility
5183** break because any application that ever receives an SQLITE_MISUSE error
5184** is broken by definition. The [SQLITE_OMIT_AUTORESET] compile-time option
5185** can be used to restore the legacy behavior.
5186**
5187** <b>Goofy Interface Alert:</b> In the legacy interface, the sqlite3_step()
5188** API always returns a generic error code, [SQLITE_ERROR], following any
5189** error other than [SQLITE_BUSY] and [SQLITE_MISUSE]. You must call
5190** [sqlite3_reset()] or [sqlite3_finalize()] in order to find one of the
5191** specific [error codes] that better describes the error.
5192** We admit that this is a goofy design. The problem has been fixed
5193** with the "v2" interface. If you prepare all of your SQL statements
5194** using [sqlite3_prepare_v3()] or [sqlite3_prepare_v2()]
5195** or [sqlite3_prepare16_v2()] or [sqlite3_prepare16_v3()] instead
5196** of the legacy [sqlite3_prepare()] and [sqlite3_prepare16()] interfaces,
5197** then the more specific [error codes] are returned directly
5198** by sqlite3_step(). The use of the "vX" interfaces is recommended.
5199*/
5200SQLITE_API int sqlite3_step(sqlite3_stmt*);
5201
5202/*
5203** CAPI3REF: Number of columns in a result set
5204** METHOD: sqlite3_stmt
5205**
5206** ^The sqlite3_data_count(P) interface returns the number of columns in the
5207** current row of the result set of [prepared statement] P.
5208** ^If prepared statement P does not have results ready to return
5209** (via calls to the [sqlite3_column_int | sqlite3_column()] family of
5210** interfaces) then sqlite3_data_count(P) returns 0.
5211** ^The sqlite3_data_count(P) routine also returns 0 if P is a NULL pointer.
5212** ^The sqlite3_data_count(P) routine returns 0 if the previous call to
5213** [sqlite3_step](P) returned [SQLITE_DONE]. ^The sqlite3_data_count(P)
5214** will return non-zero if previous call to [sqlite3_step](P) returned
5215** [SQLITE_ROW], except in the case of the [PRAGMA incremental_vacuum]
5216** where it always returns zero since each step of that multi-step
5217** pragma returns 0 columns of data.
5218**
5219** See also: [sqlite3_column_count()]
5220*/
5221SQLITE_API int sqlite3_data_count(sqlite3_stmt *pStmt);
5222
5223/*
5224** CAPI3REF: Fundamental Datatypes
5225** KEYWORDS: SQLITE_TEXT
5226**
5227** ^(Every value in SQLite has one of five fundamental datatypes:
5228**
5229** <ul>
5230** <li> 64-bit signed integer
5231** <li> 64-bit IEEE floating point number
5232** <li> string
5233** <li> BLOB
5234** <li> NULL
5235** </ul>)^
5236**
5237** These constants are codes for each of those types.
5238**
5239** Note that the SQLITE_TEXT constant was also used in SQLite version 2
5240** for a completely different meaning. Software that links against both
5241** SQLite version 2 and SQLite version 3 should use SQLITE3_TEXT, not
5242** SQLITE_TEXT.
5243*/
5244#define SQLITE_INTEGER 1
5245#define SQLITE_FLOAT 2
5246#define SQLITE_BLOB 4
5247#define SQLITE_NULL 5
5248#ifdef SQLITE_TEXT
5249# undef SQLITE_TEXT
5250#else
5251# define SQLITE_TEXT 3
5252#endif
5253#define SQLITE3_TEXT 3
5254
5255/*
5256** CAPI3REF: Result Values From A Query
5257** KEYWORDS: {column access functions}
5258** METHOD: sqlite3_stmt
5259**
5260** <b>Summary:</b>
5261** <blockquote><table border=0 cellpadding=0 cellspacing=0>
5262** <tr><td><b>sqlite3_column_blob</b><td>→<td>BLOB result
5263** <tr><td><b>sqlite3_column_double</b><td>→<td>REAL result
5264** <tr><td><b>sqlite3_column_int</b><td>→<td>32-bit INTEGER result
5265** <tr><td><b>sqlite3_column_int64</b><td>→<td>64-bit INTEGER result
5266** <tr><td><b>sqlite3_column_text</b><td>→<td>UTF-8 TEXT result
5267** <tr><td><b>sqlite3_column_text16</b><td>→<td>UTF-16 TEXT result
5268** <tr><td><b>sqlite3_column_value</b><td>→<td>The result as an
5269** [sqlite3_value|unprotected sqlite3_value] object.
5270** <tr><td> <td> <td>
5271** <tr><td><b>sqlite3_column_bytes</b><td>→<td>Size of a BLOB
5272** or a UTF-8 TEXT result in bytes
5273** <tr><td><b>sqlite3_column_bytes16 </b>
5274** <td>→ <td>Size of UTF-16
5275** TEXT in bytes
5276** <tr><td><b>sqlite3_column_type</b><td>→<td>Default
5277** datatype of the result
5278** </table></blockquote>
5279**
5280** <b>Details:</b>
5281**
5282** ^These routines return information about a single column of the current
5283** result row of a query. ^In every case the first argument is a pointer
5284** to the [prepared statement] that is being evaluated (the [sqlite3_stmt*]
5285** that was returned from [sqlite3_prepare_v2()] or one of its variants)
5286** and the second argument is the index of the column for which information
5287** should be returned. ^The leftmost column of the result set has the index 0.
5288** ^The number of columns in the result can be determined using
5289** [sqlite3_column_count()].
5290**
5291** If the SQL statement does not currently point to a valid row, or if the
5292** column index is out of range, the result is undefined.
5293** These routines may only be called when the most recent call to
5294** [sqlite3_step()] has returned [SQLITE_ROW] and neither
5295** [sqlite3_reset()] nor [sqlite3_finalize()] have been called subsequently.
5296** If any of these routines are called after [sqlite3_reset()] or
5297** [sqlite3_finalize()] or after [sqlite3_step()] has returned
5298** something other than [SQLITE_ROW], the results are undefined.
5299** If [sqlite3_step()] or [sqlite3_reset()] or [sqlite3_finalize()]
5300** are called from a different thread while any of these routines
5301** are pending, then the results are undefined.
5302**
5303** The first six interfaces (_blob, _double, _int, _int64, _text, and _text16)
5304** each return the value of a result column in a specific data format. If
5305** the result column is not initially in the requested format (for example,
5306** if the query returns an integer but the sqlite3_column_text() interface
5307** is used to extract the value) then an automatic type conversion is performed.
5308**
5309** ^The sqlite3_column_type() routine returns the
5310** [SQLITE_INTEGER | datatype code] for the initial data type
5311** of the result column. ^The returned value is one of [SQLITE_INTEGER],
5312** [SQLITE_FLOAT], [SQLITE_TEXT], [SQLITE_BLOB], or [SQLITE_NULL].
5313** The return value of sqlite3_column_type() can be used to decide which
5314** of the first six interface should be used to extract the column value.
5315** The value returned by sqlite3_column_type() is only meaningful if no
5316** automatic type conversions have occurred for the value in question.
5317** After a type conversion, the result of calling sqlite3_column_type()
5318** is undefined, though harmless. Future
5319** versions of SQLite may change the behavior of sqlite3_column_type()
5320** following a type conversion.
5321**
5322** If the result is a BLOB or a TEXT string, then the sqlite3_column_bytes()
5323** or sqlite3_column_bytes16() interfaces can be used to determine the size
5324** of that BLOB or string.
5325**
5326** ^If the result is a BLOB or UTF-8 string then the sqlite3_column_bytes()
5327** routine returns the number of bytes in that BLOB or string.
5328** ^If the result is a UTF-16 string, then sqlite3_column_bytes() converts
5329** the string to UTF-8 and then returns the number of bytes.
5330** ^If the result is a numeric value then sqlite3_column_bytes() uses
5331** [sqlite3_snprintf()] to convert that value to a UTF-8 string and returns
5332** the number of bytes in that string.
5333** ^If the result is NULL, then sqlite3_column_bytes() returns zero.
5334**
5335** ^If the result is a BLOB or UTF-16 string then the sqlite3_column_bytes16()
5336** routine returns the number of bytes in that BLOB or string.
5337** ^If the result is a UTF-8 string, then sqlite3_column_bytes16() converts
5338** the string to UTF-16 and then returns the number of bytes.
5339** ^If the result is a numeric value then sqlite3_column_bytes16() uses
5340** [sqlite3_snprintf()] to convert that value to a UTF-16 string and returns
5341** the number of bytes in that string.
5342** ^If the result is NULL, then sqlite3_column_bytes16() returns zero.
5343**
5344** ^The values returned by [sqlite3_column_bytes()] and
5345** [sqlite3_column_bytes16()] do not include the zero terminators at the end
5346** of the string. ^For clarity: the values returned by
5347** [sqlite3_column_bytes()] and [sqlite3_column_bytes16()] are the number of
5348** bytes in the string, not the number of characters.
5349**
5350** ^Strings returned by sqlite3_column_text() and sqlite3_column_text16(),
5351** even empty strings, are always zero-terminated. ^The return
5352** value from sqlite3_column_blob() for a zero-length BLOB is a NULL pointer.
5353**
5354** ^Strings returned by sqlite3_column_text16() always have the endianness
5355** which is native to the platform, regardless of the text encoding set
5356** for the database.
5357**
5358** <b>Warning:</b> ^The object returned by [sqlite3_column_value()] is an
5359** [unprotected sqlite3_value] object. In a multithreaded environment,
5360** an unprotected sqlite3_value object may only be used safely with
5361** [sqlite3_bind_value()] and [sqlite3_result_value()].
5362** If the [unprotected sqlite3_value] object returned by
5363** [sqlite3_column_value()] is used in any other way, including calls
5364** to routines like [sqlite3_value_int()], [sqlite3_value_text()],
5365** or [sqlite3_value_bytes()], the behavior is not threadsafe.
5366** Hence, the sqlite3_column_value() interface
5367** is normally only useful within the implementation of
5368** [application-defined SQL functions] or [virtual tables], not within
5369** top-level application code.
5370**
5371** These routines may attempt to convert the datatype of the result.
5372** ^For example, if the internal representation is FLOAT and a text result
5373** is requested, [sqlite3_snprintf()] is used internally to perform the
5374** conversion automatically. ^(The following table details the conversions
5375** that are applied:
5376**
5377** <blockquote>
5378** <table border="1">
5379** <tr><th> Internal<br>Type <th> Requested<br>Type <th> Conversion
5380**
5381** <tr><td> NULL <td> INTEGER <td> Result is 0
5382** <tr><td> NULL <td> FLOAT <td> Result is 0.0
5383** <tr><td> NULL <td> TEXT <td> Result is a NULL pointer
5384** <tr><td> NULL <td> BLOB <td> Result is a NULL pointer
5385** <tr><td> INTEGER <td> FLOAT <td> Convert from integer to float
5386** <tr><td> INTEGER <td> TEXT <td> ASCII rendering of the integer
5387** <tr><td> INTEGER <td> BLOB <td> Same as INTEGER->TEXT
5388** <tr><td> FLOAT <td> INTEGER <td> [CAST] to INTEGER
5389** <tr><td> FLOAT <td> TEXT <td> ASCII rendering of the float
5390** <tr><td> FLOAT <td> BLOB <td> [CAST] to BLOB
5391** <tr><td> TEXT <td> INTEGER <td> [CAST] to INTEGER
5392** <tr><td> TEXT <td> FLOAT <td> [CAST] to REAL
5393** <tr><td> TEXT <td> BLOB <td> No change
5394** <tr><td> BLOB <td> INTEGER <td> [CAST] to INTEGER
5395** <tr><td> BLOB <td> FLOAT <td> [CAST] to REAL
5396** <tr><td> BLOB <td> TEXT <td> [CAST] to TEXT, ensure zero terminator
5397** </table>
5398** </blockquote>)^
5399**
5400** Note that when type conversions occur, pointers returned by prior
5401** calls to sqlite3_column_blob(), sqlite3_column_text(), and/or
5402** sqlite3_column_text16() may be invalidated.
5403** Type conversions and pointer invalidations might occur
5404** in the following cases:
5405**
5406** <ul>
5407** <li> The initial content is a BLOB and sqlite3_column_text() or
5408** sqlite3_column_text16() is called. A zero-terminator might
5409** need to be added to the string.</li>
5410** <li> The initial content is UTF-8 text and sqlite3_column_bytes16() or
5411** sqlite3_column_text16() is called. The content must be converted
5412** to UTF-16.</li>
5413** <li> The initial content is UTF-16 text and sqlite3_column_bytes() or
5414** sqlite3_column_text() is called. The content must be converted
5415** to UTF-8.</li>
5416** </ul>
5417**
5418** ^Conversions between UTF-16be and UTF-16le are always done in place and do
5419** not invalidate a prior pointer, though of course the content of the buffer
5420** that the prior pointer references will have been modified. Other kinds
5421** of conversion are done in place when it is possible, but sometimes they
5422** are not possible and in those cases prior pointers are invalidated.
5423**
5424** The safest policy is to invoke these routines
5425** in one of the following ways:
5426**
5427** <ul>
5428** <li>sqlite3_column_text() followed by sqlite3_column_bytes()</li>
5429** <li>sqlite3_column_blob() followed by sqlite3_column_bytes()</li>
5430** <li>sqlite3_column_text16() followed by sqlite3_column_bytes16()</li>
5431** </ul>
5432**
5433** In other words, you should call sqlite3_column_text(),
5434** sqlite3_column_blob(), or sqlite3_column_text16() first to force the result
5435** into the desired format, then invoke sqlite3_column_bytes() or
5436** sqlite3_column_bytes16() to find the size of the result. Do not mix calls
5437** to sqlite3_column_text() or sqlite3_column_blob() with calls to
5438** sqlite3_column_bytes16(), and do not mix calls to sqlite3_column_text16()
5439** with calls to sqlite3_column_bytes().
5440**
5441** ^The pointers returned are valid until a type conversion occurs as
5442** described above, or until [sqlite3_step()] or [sqlite3_reset()] or
5443** [sqlite3_finalize()] is called. ^The memory space used to hold strings
5444** and BLOBs is freed automatically. Do not pass the pointers returned
5445** from [sqlite3_column_blob()], [sqlite3_column_text()], etc. into
5446** [sqlite3_free()].
5447**
5448** As long as the input parameters are correct, these routines will only
5449** fail if an out-of-memory error occurs during a format conversion.
5450** Only the following subset of interfaces are subject to out-of-memory
5451** errors:
5452**
5453** <ul>
5454** <li> sqlite3_column_blob()
5455** <li> sqlite3_column_text()
5456** <li> sqlite3_column_text16()
5457** <li> sqlite3_column_bytes()
5458** <li> sqlite3_column_bytes16()
5459** </ul>
5460**
5461** If an out-of-memory error occurs, then the return value from these
5462** routines is the same as if the column had contained an SQL NULL value.
5463** Valid SQL NULL returns can be distinguished from out-of-memory errors
5464** by invoking the [sqlite3_errcode()] immediately after the suspect
5465** return value is obtained and before any
5466** other SQLite interface is called on the same [database connection].
5467*/
5468SQLITE_API const void *sqlite3_column_blob(sqlite3_stmt*, int iCol);
5469SQLITE_API double sqlite3_column_double(sqlite3_stmt*, int iCol);
5470SQLITE_API int sqlite3_column_int(sqlite3_stmt*, int iCol);
5471SQLITE_API sqlite3_int64 sqlite3_column_int64(sqlite3_stmt*, int iCol);
5472SQLITE_API const unsigned char *sqlite3_column_text(sqlite3_stmt*, int iCol);
5473SQLITE_API const void *sqlite3_column_text16(sqlite3_stmt*, int iCol);
5474SQLITE_API sqlite3_value *sqlite3_column_value(sqlite3_stmt*, int iCol);
5475SQLITE_API int sqlite3_column_bytes(sqlite3_stmt*, int iCol);
5476SQLITE_API int sqlite3_column_bytes16(sqlite3_stmt*, int iCol);
5477SQLITE_API int sqlite3_column_type(sqlite3_stmt*, int iCol);
5478
5479/*
5480** CAPI3REF: Destroy A Prepared Statement Object
5481** DESTRUCTOR: sqlite3_stmt
5482**
5483** ^The sqlite3_finalize() function is called to delete a [prepared statement].
5484** ^If the most recent evaluation of the statement encountered no errors
5485** or if the statement is never been evaluated, then sqlite3_finalize() returns
5486** SQLITE_OK. ^If the most recent evaluation of statement S failed, then
5487** sqlite3_finalize(S) returns the appropriate [error code] or
5488** [extended error code].
5489**
5490** ^The sqlite3_finalize(S) routine can be called at any point during
5491** the life cycle of [prepared statement] S:
5492** before statement S is ever evaluated, after
5493** one or more calls to [sqlite3_reset()], or after any call
5494** to [sqlite3_step()] regardless of whether or not the statement has
5495** completed execution.
5496**
5497** ^Invoking sqlite3_finalize() on a NULL pointer is a harmless no-op.
5498**
5499** The application must finalize every [prepared statement] in order to avoid
5500** resource leaks. It is a grievous error for the application to try to use
5501** a prepared statement after it has been finalized. Any use of a prepared
5502** statement after it has been finalized can result in undefined and
5503** undesirable behavior such as segfaults and heap corruption.
5504*/
5505SQLITE_API int sqlite3_finalize(sqlite3_stmt *pStmt);
5506
5507/*
5508** CAPI3REF: Reset A Prepared Statement Object
5509** METHOD: sqlite3_stmt
5510**
5511** The sqlite3_reset() function is called to reset a [prepared statement]
5512** object back to its initial state, ready to be re-executed.
5513** ^Any SQL statement variables that had values bound to them using
5514** the [sqlite3_bind_blob | sqlite3_bind_*() API] retain their values.
5515** Use [sqlite3_clear_bindings()] to reset the bindings.
5516**
5517** ^The [sqlite3_reset(S)] interface resets the [prepared statement] S
5518** back to the beginning of its program.
5519**
5520** ^The return code from [sqlite3_reset(S)] indicates whether or not
5521** the previous evaluation of prepared statement S completed successfully.
5522** ^If [sqlite3_step(S)] has never before been called on S or if
5523** [sqlite3_step(S)] has not been called since the previous call
5524** to [sqlite3_reset(S)], then [sqlite3_reset(S)] will return
5525** [SQLITE_OK].
5526**
5527** ^If the most recent call to [sqlite3_step(S)] for the
5528** [prepared statement] S indicated an error, then
5529** [sqlite3_reset(S)] returns an appropriate [error code].
5530** ^The [sqlite3_reset(S)] interface might also return an [error code]
5531** if there were no prior errors but the process of resetting
5532** the prepared statement caused a new error. ^For example, if an
5533** [INSERT] statement with a [RETURNING] clause is only stepped one time,
5534** that one call to [sqlite3_step(S)] might return SQLITE_ROW but
5535** the overall statement might still fail and the [sqlite3_reset(S)] call
5536** might return SQLITE_BUSY if locking constraints prevent the
5537** database change from committing. Therefore, it is important that
5538** applications check the return code from [sqlite3_reset(S)] even if
5539** no prior call to [sqlite3_step(S)] indicated a problem.
5540**
5541** ^The [sqlite3_reset(S)] interface does not change the values
5542** of any [sqlite3_bind_blob|bindings] on the [prepared statement] S.
5543*/
5544SQLITE_API int sqlite3_reset(sqlite3_stmt *pStmt);
5545
5546
5547/*
5548** CAPI3REF: Create Or Redefine SQL Functions
5549** KEYWORDS: {function creation routines}
5550** METHOD: sqlite3
5551**
5552** ^These functions (collectively known as "function creation routines")
5553** are used to add SQL functions or aggregates or to redefine the behavior
5554** of existing SQL functions or aggregates. The only differences between
5555** the three "sqlite3_create_function*" routines are the text encoding
5556** expected for the second parameter (the name of the function being
5557** created) and the presence or absence of a destructor callback for
5558** the application data pointer. Function sqlite3_create_window_function()
5559** is similar, but allows the user to supply the extra callback functions
5560** needed by [aggregate window functions].
5561**
5562** ^The first parameter is the [database connection] to which the SQL
5563** function is to be added. ^If an application uses more than one database
5564** connection then application-defined SQL functions must be added
5565** to each database connection separately.
5566**
5567** ^The second parameter is the name of the SQL function to be created or
5568** redefined. ^The length of the name is limited to 255 bytes in a UTF-8
5569** representation, exclusive of the zero-terminator. ^Note that the name
5570** length limit is in UTF-8 bytes, not characters nor UTF-16 bytes.
5571** ^Any attempt to create a function with a longer name
5572** will result in [SQLITE_MISUSE] being returned.
5573**
5574** ^The third parameter (nArg)
5575** is the number of arguments that the SQL function or
5576** aggregate takes. ^If this parameter is -1, then the SQL function or
5577** aggregate may take any number of arguments between 0 and the limit
5578** set by [sqlite3_limit]([SQLITE_LIMIT_FUNCTION_ARG]). If the third
5579** parameter is less than -1 or greater than 127 then the behavior is
5580** undefined.
5581**
5582** ^The fourth parameter, eTextRep, specifies what
5583** [SQLITE_UTF8 | text encoding] this SQL function prefers for
5584** its parameters. The application should set this parameter to
5585** [SQLITE_UTF16LE] if the function implementation invokes
5586** [sqlite3_value_text16le()] on an input, or [SQLITE_UTF16BE] if the
5587** implementation invokes [sqlite3_value_text16be()] on an input, or
5588** [SQLITE_UTF16] if [sqlite3_value_text16()] is used, or [SQLITE_UTF8]
5589** otherwise. ^The same SQL function may be registered multiple times using
5590** different preferred text encodings, with different implementations for
5591** each encoding.
5592** ^When multiple implementations of the same function are available, SQLite
5593** will pick the one that involves the least amount of data conversion.
5594**
5595** ^The fourth parameter may optionally be ORed with [SQLITE_DETERMINISTIC]
5596** to signal that the function will always return the same result given
5597** the same inputs within a single SQL statement. Most SQL functions are
5598** deterministic. The built-in [random()] SQL function is an example of a
5599** function that is not deterministic. The SQLite query planner is able to
5600** perform additional optimizations on deterministic functions, so use
5601** of the [SQLITE_DETERMINISTIC] flag is recommended where possible.
5602**
5603** ^The fourth parameter may also optionally include the [SQLITE_DIRECTONLY]
5604** flag, which if present prevents the function from being invoked from
5605** within VIEWs, TRIGGERs, CHECK constraints, generated column expressions,
5606** index expressions, or the WHERE clause of partial indexes.
5607**
5608** For best security, the [SQLITE_DIRECTONLY] flag is recommended for
5609** all application-defined SQL functions that do not need to be
5610** used inside of triggers, views, CHECK constraints, or other elements of
5611** the database schema. This flag is especially recommended for SQL
5612** functions that have side effects or reveal internal application state.
5613** Without this flag, an attacker might be able to modify the schema of
5614** a database file to include invocations of the function with parameters
5615** chosen by the attacker, which the application will then execute when
5616** the database file is opened and read.
5617**
5618** ^(The fifth parameter is an arbitrary pointer. The implementation of the
5619** function can gain access to this pointer using [sqlite3_user_data()].)^
5620**
5621** ^The sixth, seventh and eighth parameters passed to the three
5622** "sqlite3_create_function*" functions, xFunc, xStep and xFinal, are
5623** pointers to C-language functions that implement the SQL function or
5624** aggregate. ^A scalar SQL function requires an implementation of the xFunc
5625** callback only; NULL pointers must be passed as the xStep and xFinal
5626** parameters. ^An aggregate SQL function requires an implementation of xStep
5627** and xFinal and NULL pointer must be passed for xFunc. ^To delete an existing
5628** SQL function or aggregate, pass NULL pointers for all three function
5629** callbacks.
5630**
5631** ^The sixth, seventh, eighth and ninth parameters (xStep, xFinal, xValue
5632** and xInverse) passed to sqlite3_create_window_function are pointers to
5633** C-language callbacks that implement the new function. xStep and xFinal
5634** must both be non-NULL. xValue and xInverse may either both be NULL, in
5635** which case a regular aggregate function is created, or must both be
5636** non-NULL, in which case the new function may be used as either an aggregate
5637** or aggregate window function. More details regarding the implementation
5638** of aggregate window functions are
5639** [user-defined window functions|available here].
5640**
5641** ^(If the final parameter to sqlite3_create_function_v2() or
5642** sqlite3_create_window_function() is not NULL, then it is the destructor for
5643** the application data pointer. The destructor is invoked when the function
5644** is deleted, either by being overloaded or when the database connection
5645** closes.)^ ^The destructor is also invoked if the call to
5646** sqlite3_create_function_v2() fails. ^When the destructor callback is
5647** invoked, it is passed a single argument which is a copy of the application
5648** data pointer which was the fifth parameter to sqlite3_create_function_v2().
5649**
5650** ^It is permitted to register multiple implementations of the same
5651** functions with the same name but with either differing numbers of
5652** arguments or differing preferred text encodings. ^SQLite will use
5653** the implementation that most closely matches the way in which the
5654** SQL function is used. ^A function implementation with a non-negative
5655** nArg parameter is a better match than a function implementation with
5656** a negative nArg. ^A function where the preferred text encoding
5657** matches the database encoding is a better
5658** match than a function where the encoding is different.
5659** ^A function where the encoding difference is between UTF16le and UTF16be
5660** is a closer match than a function where the encoding difference is
5661** between UTF8 and UTF16.
5662**
5663** ^Built-in functions may be overloaded by new application-defined functions.
5664**
5665** ^An application-defined function is permitted to call other
5666** SQLite interfaces. However, such calls must not
5667** close the database connection nor finalize or reset the prepared
5668** statement in which the function is running.
5669*/
5670SQLITE_API int sqlite3_create_function(
5671 sqlite3 *db,
5672 const char *zFunctionName,
5673 int nArg,
5674 int eTextRep,
5675 void *pApp,
5676 void (*xFunc)(sqlite3_context*,int,sqlite3_value**),
5677 void (*xStep)(sqlite3_context*,int,sqlite3_value**),
5678 void (*xFinal)(sqlite3_context*)
5679);
5680SQLITE_API int sqlite3_create_function16(
5681 sqlite3 *db,
5682 const void *zFunctionName,
5683 int nArg,
5684 int eTextRep,
5685 void *pApp,
5686 void (*xFunc)(sqlite3_context*,int,sqlite3_value**),
5687 void (*xStep)(sqlite3_context*,int,sqlite3_value**),
5688 void (*xFinal)(sqlite3_context*)
5689);
5690SQLITE_API int sqlite3_create_function_v2(
5691 sqlite3 *db,
5692 const char *zFunctionName,
5693 int nArg,
5694 int eTextRep,
5695 void *pApp,
5696 void (*xFunc)(sqlite3_context*,int,sqlite3_value**),
5697 void (*xStep)(sqlite3_context*,int,sqlite3_value**),
5698 void (*xFinal)(sqlite3_context*),
5699 void(*xDestroy)(void*)
5700);
5701SQLITE_API int sqlite3_create_window_function(
5702 sqlite3 *db,
5703 const char *zFunctionName,
5704 int nArg,
5705 int eTextRep,
5706 void *pApp,
5707 void (*xStep)(sqlite3_context*,int,sqlite3_value**),
5708 void (*xFinal)(sqlite3_context*),
5709 void (*xValue)(sqlite3_context*),
5710 void (*xInverse)(sqlite3_context*,int,sqlite3_value**),
5711 void(*xDestroy)(void*)
5712);
5713
5714/*
5715** CAPI3REF: Text Encodings
5716**
5717** These constant define integer codes that represent the various
5718** text encodings supported by SQLite.
5719*/
5720#define SQLITE_UTF8 1 /* IMP: R-37514-35566 */
5721#define SQLITE_UTF16LE 2 /* IMP: R-03371-37637 */
5722#define SQLITE_UTF16BE 3 /* IMP: R-51971-34154 */
5723#define SQLITE_UTF16 4 /* Use native byte order */
5724#define SQLITE_ANY 5 /* Deprecated */
5725#define SQLITE_UTF16_ALIGNED 8 /* sqlite3_create_collation only */
5726
5727/*
5728** CAPI3REF: Function Flags
5729**
5730** These constants may be ORed together with the
5731** [SQLITE_UTF8 | preferred text encoding] as the fourth argument
5732** to [sqlite3_create_function()], [sqlite3_create_function16()], or
5733** [sqlite3_create_function_v2()].
5734**
5735** <dl>
5736** [[SQLITE_DETERMINISTIC]] <dt>SQLITE_DETERMINISTIC</dt><dd>
5737** The SQLITE_DETERMINISTIC flag means that the new function always gives
5738** the same output when the input parameters are the same.
5739** The [abs|abs() function] is deterministic, for example, but
5740** [randomblob|randomblob()] is not. Functions must
5741** be deterministic in order to be used in certain contexts such as
5742** with the WHERE clause of [partial indexes] or in [generated columns].
5743** SQLite might also optimize deterministic functions by factoring them
5744** out of inner loops.
5745** </dd>
5746**
5747** [[SQLITE_DIRECTONLY]] <dt>SQLITE_DIRECTONLY</dt><dd>
5748** The SQLITE_DIRECTONLY flag means that the function may only be invoked
5749** from top-level SQL, and cannot be used in VIEWs or TRIGGERs nor in
5750** schema structures such as [CHECK constraints], [DEFAULT clauses],
5751** [expression indexes], [partial indexes], or [generated columns].
5752** <p>
5753** The SQLITE_DIRECTONLY flag is recommended for any
5754** [application-defined SQL function]
5755** that has side-effects or that could potentially leak sensitive information.
5756** This will prevent attacks in which an application is tricked
5757** into using a database file that has had its schema surreptitiously
5758** modified to invoke the application-defined function in ways that are
5759** harmful.
5760** <p>
5761** Some people say it is good practice to set SQLITE_DIRECTONLY on all
5762** [application-defined SQL functions], regardless of whether or not they
5763** are security sensitive, as doing so prevents those functions from being used
5764** inside of the database schema, and thus ensures that the database
5765** can be inspected and modified using generic tools (such as the [CLI])
5766** that do not have access to the application-defined functions.
5767** </dd>
5768**
5769** [[SQLITE_INNOCUOUS]] <dt>SQLITE_INNOCUOUS</dt><dd>
5770** The SQLITE_INNOCUOUS flag means that the function is unlikely
5771** to cause problems even if misused. An innocuous function should have
5772** no side effects and should not depend on any values other than its
5773** input parameters. The [abs|abs() function] is an example of an
5774** innocuous function.
5775** The [load_extension() SQL function] is not innocuous because of its
5776** side effects.
5777** <p> SQLITE_INNOCUOUS is similar to SQLITE_DETERMINISTIC, but is not
5778** exactly the same. The [random|random() function] is an example of a
5779** function that is innocuous but not deterministic.
5780** <p>Some heightened security settings
5781** ([SQLITE_DBCONFIG_TRUSTED_SCHEMA] and [PRAGMA trusted_schema=OFF])
5782** disable the use of SQL functions inside views and triggers and in
5783** schema structures such as [CHECK constraints], [DEFAULT clauses],
5784** [expression indexes], [partial indexes], and [generated columns] unless
5785** the function is tagged with SQLITE_INNOCUOUS. Most built-in functions
5786** are innocuous. Developers are advised to avoid using the
5787** SQLITE_INNOCUOUS flag for application-defined functions unless the
5788** function has been carefully audited and found to be free of potentially
5789** security-adverse side-effects and information-leaks.
5790** </dd>
5791**
5792** [[SQLITE_SUBTYPE]] <dt>SQLITE_SUBTYPE</dt><dd>
5793** The SQLITE_SUBTYPE flag indicates to SQLite that a function might call
5794** [sqlite3_value_subtype()] to inspect the sub-types of its arguments.
5795** This flag instructs SQLite to omit some corner-case optimizations that
5796** might disrupt the operation of the [sqlite3_value_subtype()] function,
5797** causing it to return zero rather than the correct subtype().
5798** All SQL functions that invoke [sqlite3_value_subtype()] should have this
5799** property. If the SQLITE_SUBTYPE property is omitted, then the return
5800** value from [sqlite3_value_subtype()] might sometimes be zero even though
5801** a non-zero subtype was specified by the function argument expression.
5802**
5803** [[SQLITE_RESULT_SUBTYPE]] <dt>SQLITE_RESULT_SUBTYPE</dt><dd>
5804** The SQLITE_RESULT_SUBTYPE flag indicates to SQLite that a function might call
5805** [sqlite3_result_subtype()] to cause a sub-type to be associated with its
5806** result.
5807** Every function that invokes [sqlite3_result_subtype()] should have this
5808** property. If it does not, then the call to [sqlite3_result_subtype()]
5809** might become a no-op if the function is used as term in an
5810** [expression index]. On the other hand, SQL functions that never invoke
5811** [sqlite3_result_subtype()] should avoid setting this property, as the
5812** purpose of this property is to disable certain optimizations that are
5813** incompatible with subtypes.
5814**
5815** [[SQLITE_SELFORDER1]] <dt>SQLITE_SELFORDER1</dt><dd>
5816** The SQLITE_SELFORDER1 flag indicates that the function is an aggregate
5817** that internally orders the values provided to the first argument. The
5818** ordered-set aggregate SQL notation with a single ORDER BY term can be
5819** used to invoke this function. If the ordered-set aggregate notation is
5820** used on a function that lacks this flag, then an error is raised. Note
5821** that the ordered-set aggregate syntax is only available if SQLite is
5822** built using the -DSQLITE_ENABLE_ORDERED_SET_AGGREGATES compile-time option.
5823** </dd>
5824** </dl>
5825*/
5826#define SQLITE_DETERMINISTIC 0x000000800
5827#define SQLITE_DIRECTONLY 0x000080000
5828#define SQLITE_SUBTYPE 0x000100000
5829#define SQLITE_INNOCUOUS 0x000200000
5830#define SQLITE_RESULT_SUBTYPE 0x001000000
5831#define SQLITE_SELFORDER1 0x002000000
5832
5833/*
5834** CAPI3REF: Deprecated Functions
5835** DEPRECATED
5836**
5837** These functions are [deprecated]. In order to maintain
5838** backwards compatibility with older code, these functions continue
5839** to be supported. However, new applications should avoid
5840** the use of these functions. To encourage programmers to avoid
5841** these functions, we will not explain what they do.
5842*/
5843#ifndef SQLITE_OMIT_DEPRECATED
5844SQLITE_API SQLITE_DEPRECATED int sqlite3_aggregate_count(sqlite3_context*);
5845SQLITE_API SQLITE_DEPRECATED int sqlite3_expired(sqlite3_stmt*);
5846SQLITE_API SQLITE_DEPRECATED int sqlite3_transfer_bindings(sqlite3_stmt*, sqlite3_stmt*);
5847SQLITE_API SQLITE_DEPRECATED int sqlite3_global_recover(void);
5848SQLITE_API SQLITE_DEPRECATED void sqlite3_thread_cleanup(void);
5849SQLITE_API SQLITE_DEPRECATED int sqlite3_memory_alarm(void(*)(void*,sqlite3_int64,int),
5850 void*,sqlite3_int64);
5851#endif
5852
5853/*
5854** CAPI3REF: Obtaining SQL Values
5855** METHOD: sqlite3_value
5856**
5857** <b>Summary:</b>
5858** <blockquote><table border=0 cellpadding=0 cellspacing=0>
5859** <tr><td><b>sqlite3_value_blob</b><td>→<td>BLOB value
5860** <tr><td><b>sqlite3_value_double</b><td>→<td>REAL value
5861** <tr><td><b>sqlite3_value_int</b><td>→<td>32-bit INTEGER value
5862** <tr><td><b>sqlite3_value_int64</b><td>→<td>64-bit INTEGER value
5863** <tr><td><b>sqlite3_value_pointer</b><td>→<td>Pointer value
5864** <tr><td><b>sqlite3_value_text</b><td>→<td>UTF-8 TEXT value
5865** <tr><td><b>sqlite3_value_text16</b><td>→<td>UTF-16 TEXT value in
5866** the native byteorder
5867** <tr><td><b>sqlite3_value_text16be</b><td>→<td>UTF-16be TEXT value
5868** <tr><td><b>sqlite3_value_text16le</b><td>→<td>UTF-16le TEXT value
5869** <tr><td> <td> <td>
5870** <tr><td><b>sqlite3_value_bytes</b><td>→<td>Size of a BLOB
5871** or a UTF-8 TEXT in bytes
5872** <tr><td><b>sqlite3_value_bytes16 </b>
5873** <td>→ <td>Size of UTF-16
5874** TEXT in bytes
5875** <tr><td><b>sqlite3_value_type</b><td>→<td>Default
5876** datatype of the value
5877** <tr><td><b>sqlite3_value_numeric_type </b>
5878** <td>→ <td>Best numeric datatype of the value
5879** <tr><td><b>sqlite3_value_nochange </b>
5880** <td>→ <td>True if the column is unchanged in an UPDATE
5881** against a virtual table.
5882** <tr><td><b>sqlite3_value_frombind </b>
5883** <td>→ <td>True if value originated from a [bound parameter]
5884** </table></blockquote>
5885**
5886** <b>Details:</b>
5887**
5888** These routines extract type, size, and content information from
5889** [protected sqlite3_value] objects. Protected sqlite3_value objects
5890** are used to pass parameter information into the functions that
5891** implement [application-defined SQL functions] and [virtual tables].
5892**
5893** These routines work only with [protected sqlite3_value] objects.
5894** Any attempt to use these routines on an [unprotected sqlite3_value]
5895** is not threadsafe.
5896**
5897** ^These routines work just like the corresponding [column access functions]
5898** except that these routines take a single [protected sqlite3_value] object
5899** pointer instead of a [sqlite3_stmt*] pointer and an integer column number.
5900**
5901** ^The sqlite3_value_text16() interface extracts a UTF-16 string
5902** in the native byte-order of the host machine. ^The
5903** sqlite3_value_text16be() and sqlite3_value_text16le() interfaces
5904** extract UTF-16 strings as big-endian and little-endian respectively.
5905**
5906** ^If [sqlite3_value] object V was initialized
5907** using [sqlite3_bind_pointer(S,I,P,X,D)] or [sqlite3_result_pointer(C,P,X,D)]
5908** and if X and Y are strings that compare equal according to strcmp(X,Y),
5909** then sqlite3_value_pointer(V,Y) will return the pointer P. ^Otherwise,
5910** sqlite3_value_pointer(V,Y) returns a NULL. The sqlite3_bind_pointer()
5911** routine is part of the [pointer passing interface] added for SQLite 3.20.0.
5912**
5913** ^(The sqlite3_value_type(V) interface returns the
5914** [SQLITE_INTEGER | datatype code] for the initial datatype of the
5915** [sqlite3_value] object V. The returned value is one of [SQLITE_INTEGER],
5916** [SQLITE_FLOAT], [SQLITE_TEXT], [SQLITE_BLOB], or [SQLITE_NULL].)^
5917** Other interfaces might change the datatype for an sqlite3_value object.
5918** For example, if the datatype is initially SQLITE_INTEGER and
5919** sqlite3_value_text(V) is called to extract a text value for that
5920** integer, then subsequent calls to sqlite3_value_type(V) might return
5921** SQLITE_TEXT. Whether or not a persistent internal datatype conversion
5922** occurs is undefined and may change from one release of SQLite to the next.
5923**
5924** ^(The sqlite3_value_numeric_type() interface attempts to apply
5925** numeric affinity to the value. This means that an attempt is
5926** made to convert the value to an integer or floating point. If
5927** such a conversion is possible without loss of information (in other
5928** words, if the value is a string that looks like a number)
5929** then the conversion is performed. Otherwise no conversion occurs.
5930** The [SQLITE_INTEGER | datatype] after conversion is returned.)^
5931**
5932** ^Within the [xUpdate] method of a [virtual table], the
5933** sqlite3_value_nochange(X) interface returns true if and only if
5934** the column corresponding to X is unchanged by the UPDATE operation
5935** that the xUpdate method call was invoked to implement and if
5936** and the prior [xColumn] method call that was invoked to extracted
5937** the value for that column returned without setting a result (probably
5938** because it queried [sqlite3_vtab_nochange()] and found that the column
5939** was unchanging). ^Within an [xUpdate] method, any value for which
5940** sqlite3_value_nochange(X) is true will in all other respects appear
5941** to be a NULL value. If sqlite3_value_nochange(X) is invoked anywhere other
5942** than within an [xUpdate] method call for an UPDATE statement, then
5943** the return value is arbitrary and meaningless.
5944**
5945** ^The sqlite3_value_frombind(X) interface returns non-zero if the
5946** value X originated from one of the [sqlite3_bind_int|sqlite3_bind()]
5947** interfaces. ^If X comes from an SQL literal value, or a table column,
5948** or an expression, then sqlite3_value_frombind(X) returns zero.
5949**
5950** Please pay particular attention to the fact that the pointer returned
5951** from [sqlite3_value_blob()], [sqlite3_value_text()], or
5952** [sqlite3_value_text16()] can be invalidated by a subsequent call to
5953** [sqlite3_value_bytes()], [sqlite3_value_bytes16()], [sqlite3_value_text()],
5954** or [sqlite3_value_text16()].
5955**
5956** These routines must be called from the same thread as
5957** the SQL function that supplied the [sqlite3_value*] parameters.
5958**
5959** As long as the input parameter is correct, these routines can only
5960** fail if an out-of-memory error occurs during a format conversion.
5961** Only the following subset of interfaces are subject to out-of-memory
5962** errors:
5963**
5964** <ul>
5965** <li> sqlite3_value_blob()
5966** <li> sqlite3_value_text()
5967** <li> sqlite3_value_text16()
5968** <li> sqlite3_value_text16le()
5969** <li> sqlite3_value_text16be()
5970** <li> sqlite3_value_bytes()
5971** <li> sqlite3_value_bytes16()
5972** </ul>
5973**
5974** If an out-of-memory error occurs, then the return value from these
5975** routines is the same as if the column had contained an SQL NULL value.
5976** Valid SQL NULL returns can be distinguished from out-of-memory errors
5977** by invoking the [sqlite3_errcode()] immediately after the suspect
5978** return value is obtained and before any
5979** other SQLite interface is called on the same [database connection].
5980*/
5981SQLITE_API const void *sqlite3_value_blob(sqlite3_value*);
5982SQLITE_API double sqlite3_value_double(sqlite3_value*);
5983SQLITE_API int sqlite3_value_int(sqlite3_value*);
5984SQLITE_API sqlite3_int64 sqlite3_value_int64(sqlite3_value*);
5985SQLITE_API void *sqlite3_value_pointer(sqlite3_value*, const char*);
5986SQLITE_API const unsigned char *sqlite3_value_text(sqlite3_value*);
5987SQLITE_API const void *sqlite3_value_text16(sqlite3_value*);
5988SQLITE_API const void *sqlite3_value_text16le(sqlite3_value*);
5989SQLITE_API const void *sqlite3_value_text16be(sqlite3_value*);
5990SQLITE_API int sqlite3_value_bytes(sqlite3_value*);
5991SQLITE_API int sqlite3_value_bytes16(sqlite3_value*);
5992SQLITE_API int sqlite3_value_type(sqlite3_value*);
5993SQLITE_API int sqlite3_value_numeric_type(sqlite3_value*);
5994SQLITE_API int sqlite3_value_nochange(sqlite3_value*);
5995SQLITE_API int sqlite3_value_frombind(sqlite3_value*);
5996
5997/*
5998** CAPI3REF: Report the internal text encoding state of an sqlite3_value object
5999** METHOD: sqlite3_value
6000**
6001** ^(The sqlite3_value_encoding(X) interface returns one of [SQLITE_UTF8],
6002** [SQLITE_UTF16BE], or [SQLITE_UTF16LE] according to the current text encoding
6003** of the value X, assuming that X has type TEXT.)^ If sqlite3_value_type(X)
6004** returns something other than SQLITE_TEXT, then the return value from
6005** sqlite3_value_encoding(X) is meaningless. ^Calls to
6006** [sqlite3_value_text(X)], [sqlite3_value_text16(X)], [sqlite3_value_text16be(X)],
6007** [sqlite3_value_text16le(X)], [sqlite3_value_bytes(X)], or
6008** [sqlite3_value_bytes16(X)] might change the encoding of the value X and
6009** thus change the return from subsequent calls to sqlite3_value_encoding(X).
6010**
6011** This routine is intended for used by applications that test and validate
6012** the SQLite implementation. This routine is inquiring about the opaque
6013** internal state of an [sqlite3_value] object. Ordinary applications should
6014** not need to know what the internal state of an sqlite3_value object is and
6015** hence should not need to use this interface.
6016*/
6017SQLITE_API int sqlite3_value_encoding(sqlite3_value*);
6018
6019/*
6020** CAPI3REF: Finding The Subtype Of SQL Values
6021** METHOD: sqlite3_value
6022**
6023** The sqlite3_value_subtype(V) function returns the subtype for
6024** an [application-defined SQL function] argument V. The subtype
6025** information can be used to pass a limited amount of context from
6026** one SQL function to another. Use the [sqlite3_result_subtype()]
6027** routine to set the subtype for the return value of an SQL function.
6028**
6029** Every [application-defined SQL function] that invokes this interface
6030** should include the [SQLITE_SUBTYPE] property in the text
6031** encoding argument when the function is [sqlite3_create_function|registered].
6032** If the [SQLITE_SUBTYPE] property is omitted, then sqlite3_value_subtype()
6033** might return zero instead of the upstream subtype in some corner cases.
6034*/
6035SQLITE_API unsigned int sqlite3_value_subtype(sqlite3_value*);
6036
6037/*
6038** CAPI3REF: Copy And Free SQL Values
6039** METHOD: sqlite3_value
6040**
6041** ^The sqlite3_value_dup(V) interface makes a copy of the [sqlite3_value]
6042** object V and returns a pointer to that copy. ^The [sqlite3_value] returned
6043** is a [protected sqlite3_value] object even if the input is not.
6044** ^The sqlite3_value_dup(V) interface returns NULL if V is NULL or if a
6045** memory allocation fails. ^If V is a [pointer value], then the result
6046** of sqlite3_value_dup(V) is a NULL value.
6047**
6048** ^The sqlite3_value_free(V) interface frees an [sqlite3_value] object
6049** previously obtained from [sqlite3_value_dup()]. ^If V is a NULL pointer
6050** then sqlite3_value_free(V) is a harmless no-op.
6051*/
6052SQLITE_API sqlite3_value *sqlite3_value_dup(const sqlite3_value*);
6053SQLITE_API void sqlite3_value_free(sqlite3_value*);
6054
6055/*
6056** CAPI3REF: Obtain Aggregate Function Context
6057** METHOD: sqlite3_context
6058**
6059** Implementations of aggregate SQL functions use this
6060** routine to allocate memory for storing their state.
6061**
6062** ^The first time the sqlite3_aggregate_context(C,N) routine is called
6063** for a particular aggregate function, SQLite allocates
6064** N bytes of memory, zeroes out that memory, and returns a pointer
6065** to the new memory. ^On second and subsequent calls to
6066** sqlite3_aggregate_context() for the same aggregate function instance,
6067** the same buffer is returned. Sqlite3_aggregate_context() is normally
6068** called once for each invocation of the xStep callback and then one
6069** last time when the xFinal callback is invoked. ^(When no rows match
6070** an aggregate query, the xStep() callback of the aggregate function
6071** implementation is never called and xFinal() is called exactly once.
6072** In those cases, sqlite3_aggregate_context() might be called for the
6073** first time from within xFinal().)^
6074**
6075** ^The sqlite3_aggregate_context(C,N) routine returns a NULL pointer
6076** when first called if N is less than or equal to zero or if a memory
6077** allocation error occurs.
6078**
6079** ^(The amount of space allocated by sqlite3_aggregate_context(C,N) is
6080** determined by the N parameter on the first successful call. Changing the
6081** value of N in any subsequent call to sqlite3_aggregate_context() within
6082** the same aggregate function instance will not resize the memory
6083** allocation.)^ Within the xFinal callback, it is customary to set
6084** N=0 in calls to sqlite3_aggregate_context(C,N) so that no
6085** pointless memory allocations occur.
6086**
6087** ^SQLite automatically frees the memory allocated by
6088** sqlite3_aggregate_context() when the aggregate query concludes.
6089**
6090** The first parameter must be a copy of the
6091** [sqlite3_context | SQL function context] that is the first parameter
6092** to the xStep or xFinal callback routine that implements the aggregate
6093** function.
6094**
6095** This routine must be called from the same thread in which
6096** the aggregate SQL function is running.
6097*/
6098SQLITE_API void *sqlite3_aggregate_context(sqlite3_context*, int nBytes);
6099
6100/*
6101** CAPI3REF: User Data For Functions
6102** METHOD: sqlite3_context
6103**
6104** ^The sqlite3_user_data() interface returns a copy of
6105** the pointer that was the pUserData parameter (the 5th parameter)
6106** of the [sqlite3_create_function()]
6107** and [sqlite3_create_function16()] routines that originally
6108** registered the application defined function.
6109**
6110** This routine must be called from the same thread in which
6111** the application-defined function is running.
6112*/
6113SQLITE_API void *sqlite3_user_data(sqlite3_context*);
6114
6115/*
6116** CAPI3REF: Database Connection For Functions
6117** METHOD: sqlite3_context
6118**
6119** ^The sqlite3_context_db_handle() interface returns a copy of
6120** the pointer to the [database connection] (the 1st parameter)
6121** of the [sqlite3_create_function()]
6122** and [sqlite3_create_function16()] routines that originally
6123** registered the application defined function.
6124*/
6125SQLITE_API sqlite3 *sqlite3_context_db_handle(sqlite3_context*);
6126
6127/*
6128** CAPI3REF: Function Auxiliary Data
6129** METHOD: sqlite3_context
6130**
6131** These functions may be used by (non-aggregate) SQL functions to
6132** associate auxiliary data with argument values. If the same argument
6133** value is passed to multiple invocations of the same SQL function during
6134** query execution, under some circumstances the associated auxiliary data
6135** might be preserved. An example of where this might be useful is in a
6136** regular-expression matching function. The compiled version of the regular
6137** expression can be stored as auxiliary data associated with the pattern string.
6138** Then as long as the pattern string remains the same,
6139** the compiled regular expression can be reused on multiple
6140** invocations of the same function.
6141**
6142** ^The sqlite3_get_auxdata(C,N) interface returns a pointer to the auxiliary data
6143** associated by the sqlite3_set_auxdata(C,N,P,X) function with the Nth argument
6144** value to the application-defined function. ^N is zero for the left-most
6145** function argument. ^If there is no auxiliary data
6146** associated with the function argument, the sqlite3_get_auxdata(C,N) interface
6147** returns a NULL pointer.
6148**
6149** ^The sqlite3_set_auxdata(C,N,P,X) interface saves P as auxiliary data for the
6150** N-th argument of the application-defined function. ^Subsequent
6151** calls to sqlite3_get_auxdata(C,N) return P from the most recent
6152** sqlite3_set_auxdata(C,N,P,X) call if the auxiliary data is still valid or
6153** NULL if the auxiliary data has been discarded.
6154** ^After each call to sqlite3_set_auxdata(C,N,P,X) where X is not NULL,
6155** SQLite will invoke the destructor function X with parameter P exactly
6156** once, when the auxiliary data is discarded.
6157** SQLite is free to discard the auxiliary data at any time, including: <ul>
6158** <li> ^(when the corresponding function parameter changes)^, or
6159** <li> ^(when [sqlite3_reset()] or [sqlite3_finalize()] is called for the
6160** SQL statement)^, or
6161** <li> ^(when sqlite3_set_auxdata() is invoked again on the same
6162** parameter)^, or
6163** <li> ^(during the original sqlite3_set_auxdata() call when a memory
6164** allocation error occurs.)^
6165** <li> ^(during the original sqlite3_set_auxdata() call if the function
6166** is evaluated during query planning instead of during query execution,
6167** as sometimes happens with [SQLITE_ENABLE_STAT4].)^ </ul>
6168**
6169** Note the last two bullets in particular. The destructor X in
6170** sqlite3_set_auxdata(C,N,P,X) might be called immediately, before the
6171** sqlite3_set_auxdata() interface even returns. Hence sqlite3_set_auxdata()
6172** should be called near the end of the function implementation and the
6173** function implementation should not make any use of P after
6174** sqlite3_set_auxdata() has been called. Furthermore, a call to
6175** sqlite3_get_auxdata() that occurs immediately after a corresponding call
6176** to sqlite3_set_auxdata() might still return NULL if an out-of-memory
6177** condition occurred during the sqlite3_set_auxdata() call or if the
6178** function is being evaluated during query planning rather than during
6179** query execution.
6180**
6181** ^(In practice, auxiliary data is preserved between function calls for
6182** function parameters that are compile-time constants, including literal
6183** values and [parameters] and expressions composed from the same.)^
6184**
6185** The value of the N parameter to these interfaces should be non-negative.
6186** Future enhancements may make use of negative N values to define new
6187** kinds of function caching behavior.
6188**
6189** These routines must be called from the same thread in which
6190** the SQL function is running.
6191**
6192** See also: [sqlite3_get_clientdata()] and [sqlite3_set_clientdata()].
6193*/
6194SQLITE_API void *sqlite3_get_auxdata(sqlite3_context*, int N);
6195SQLITE_API void sqlite3_set_auxdata(sqlite3_context*, int N, void*, void (*)(void*));
6196
6197/*
6198** CAPI3REF: Database Connection Client Data
6199** METHOD: sqlite3
6200**
6201** These functions are used to associate one or more named pointers
6202** with a [database connection].
6203** A call to sqlite3_set_clientdata(D,N,P,X) causes the pointer P
6204** to be attached to [database connection] D using name N. Subsequent
6205** calls to sqlite3_get_clientdata(D,N) will return a copy of pointer P
6206** or a NULL pointer if there were no prior calls to
6207** sqlite3_set_clientdata() with the same values of D and N.
6208** Names are compared using strcmp() and are thus case sensitive.
6209**
6210** If P and X are both non-NULL, then the destructor X is invoked with
6211** argument P on the first of the following occurrences:
6212** <ul>
6213** <li> An out-of-memory error occurs during the call to
6214** sqlite3_set_clientdata() which attempts to register pointer P.
6215** <li> A subsequent call to sqlite3_set_clientdata(D,N,P,X) is made
6216** with the same D and N parameters.
6217** <li> The database connection closes. SQLite does not make any guarantees
6218** about the order in which destructors are called, only that all
6219** destructors will be called exactly once at some point during the
6220** database connection closing process.
6221** </ul>
6222**
6223** SQLite does not do anything with client data other than invoke
6224** destructors on the client data at the appropriate time. The intended
6225** use for client data is to provide a mechanism for wrapper libraries
6226** to store additional information about an SQLite database connection.
6227**
6228** There is no limit (other than available memory) on the number of different
6229** client data pointers (with different names) that can be attached to a
6230** single database connection. However, the implementation is optimized
6231** for the case of having only one or two different client data names.
6232** Applications and wrapper libraries are discouraged from using more than
6233** one client data name each.
6234**
6235** There is no way to enumerate the client data pointers
6236** associated with a database connection. The N parameter can be thought
6237** of as a secret key such that only code that knows the secret key is able
6238** to access the associated data.
6239**
6240** Security Warning: These interfaces should not be exposed in scripting
6241** languages or in other circumstances where it might be possible for an
6242** attacker to invoke them. Any agent that can invoke these interfaces
6243** can probably also take control of the process.
6244**
6245** Database connection client data is only available for SQLite
6246** version 3.44.0 ([dateof:3.44.0]) and later.
6247**
6248** See also: [sqlite3_set_auxdata()] and [sqlite3_get_auxdata()].
6249*/
6250SQLITE_API void *sqlite3_get_clientdata(sqlite3*,const char*);
6251SQLITE_API int sqlite3_set_clientdata(sqlite3*, const char*, void*, void(*)(void*));
6252
6253/*
6254** CAPI3REF: Constants Defining Special Destructor Behavior
6255**
6256** These are special values for the destructor that is passed in as the
6257** final argument to routines like [sqlite3_result_blob()]. ^If the destructor
6258** argument is SQLITE_STATIC, it means that the content pointer is constant
6259** and will never change. It does not need to be destroyed. ^The
6260** SQLITE_TRANSIENT value means that the content will likely change in
6261** the near future and that SQLite should make its own private copy of
6262** the content before returning.
6263**
6264** The typedef is necessary to work around problems in certain
6265** C++ compilers.
6266*/
6267typedef void (*sqlite3_destructor_type)(void*);
6268#define SQLITE_STATIC ((sqlite3_destructor_type)0)
6269#define SQLITE_TRANSIENT ((sqlite3_destructor_type)-1)
6270
6271/*
6272** CAPI3REF: Setting The Result Of An SQL Function
6273** METHOD: sqlite3_context
6274**
6275** These routines are used by the xFunc or xFinal callbacks that
6276** implement SQL functions and aggregates. See
6277** [sqlite3_create_function()] and [sqlite3_create_function16()]
6278** for additional information.
6279**
6280** These functions work very much like the [parameter binding] family of
6281** functions used to bind values to host parameters in prepared statements.
6282** Refer to the [SQL parameter] documentation for additional information.
6283**
6284** ^The sqlite3_result_blob() interface sets the result from
6285** an application-defined function to be the BLOB whose content is pointed
6286** to by the second parameter and which is N bytes long where N is the
6287** third parameter.
6288**
6289** ^The sqlite3_result_zeroblob(C,N) and sqlite3_result_zeroblob64(C,N)
6290** interfaces set the result of the application-defined function to be
6291** a BLOB containing all zero bytes and N bytes in size.
6292**
6293** ^The sqlite3_result_double() interface sets the result from
6294** an application-defined function to be a floating point value specified
6295** by its 2nd argument.
6296**
6297** ^The sqlite3_result_error() and sqlite3_result_error16() functions
6298** cause the implemented SQL function to throw an exception.
6299** ^SQLite uses the string pointed to by the
6300** 2nd parameter of sqlite3_result_error() or sqlite3_result_error16()
6301** as the text of an error message. ^SQLite interprets the error
6302** message string from sqlite3_result_error() as UTF-8. ^SQLite
6303** interprets the string from sqlite3_result_error16() as UTF-16 using
6304** the same [byte-order determination rules] as [sqlite3_bind_text16()].
6305** ^If the third parameter to sqlite3_result_error()
6306** or sqlite3_result_error16() is negative then SQLite takes as the error
6307** message all text up through the first zero character.
6308** ^If the third parameter to sqlite3_result_error() or
6309** sqlite3_result_error16() is non-negative then SQLite takes that many
6310** bytes (not characters) from the 2nd parameter as the error message.
6311** ^The sqlite3_result_error() and sqlite3_result_error16()
6312** routines make a private copy of the error message text before
6313** they return. Hence, the calling function can deallocate or
6314** modify the text after they return without harm.
6315** ^The sqlite3_result_error_code() function changes the error code
6316** returned by SQLite as a result of an error in a function. ^By default,
6317** the error code is SQLITE_ERROR. ^A subsequent call to sqlite3_result_error()
6318** or sqlite3_result_error16() resets the error code to SQLITE_ERROR.
6319**
6320** ^The sqlite3_result_error_toobig() interface causes SQLite to throw an
6321** error indicating that a string or BLOB is too long to represent.
6322**
6323** ^The sqlite3_result_error_nomem() interface causes SQLite to throw an
6324** error indicating that a memory allocation failed.
6325**
6326** ^The sqlite3_result_int() interface sets the return value
6327** of the application-defined function to be the 32-bit signed integer
6328** value given in the 2nd argument.
6329** ^The sqlite3_result_int64() interface sets the return value
6330** of the application-defined function to be the 64-bit signed integer
6331** value given in the 2nd argument.
6332**
6333** ^The sqlite3_result_null() interface sets the return value
6334** of the application-defined function to be NULL.
6335**
6336** ^The sqlite3_result_text(), sqlite3_result_text16(),
6337** sqlite3_result_text16le(), and sqlite3_result_text16be() interfaces
6338** set the return value of the application-defined function to be
6339** a text string which is represented as UTF-8, UTF-16 native byte order,
6340** UTF-16 little endian, or UTF-16 big endian, respectively.
6341** ^The sqlite3_result_text64() interface sets the return value of an
6342** application-defined function to be a text string in an encoding
6343** specified by the fifth (and last) parameter, which must be one
6344** of [SQLITE_UTF8], [SQLITE_UTF16], [SQLITE_UTF16BE], or [SQLITE_UTF16LE].
6345** ^SQLite takes the text result from the application from
6346** the 2nd parameter of the sqlite3_result_text* interfaces.
6347** ^If the 3rd parameter to any of the sqlite3_result_text* interfaces
6348** other than sqlite3_result_text64() is negative, then SQLite computes
6349** the string length itself by searching the 2nd parameter for the first
6350** zero character.
6351** ^If the 3rd parameter to the sqlite3_result_text* interfaces
6352** is non-negative, then as many bytes (not characters) of the text
6353** pointed to by the 2nd parameter are taken as the application-defined
6354** function result. If the 3rd parameter is non-negative, then it
6355** must be the byte offset into the string where the NUL terminator would
6356** appear if the string were NUL terminated. If any NUL characters occur
6357** in the string at a byte offset that is less than the value of the 3rd
6358** parameter, then the resulting string will contain embedded NULs and the
6359** result of expressions operating on strings with embedded NULs is undefined.
6360** ^If the 4th parameter to the sqlite3_result_text* interfaces
6361** or sqlite3_result_blob is a non-NULL pointer, then SQLite calls that
6362** function as the destructor on the text or BLOB result when it has
6363** finished using that result.
6364** ^If the 4th parameter to the sqlite3_result_text* interfaces or to
6365** sqlite3_result_blob is the special constant SQLITE_STATIC, then SQLite
6366** assumes that the text or BLOB result is in constant space and does not
6367** copy the content of the parameter nor call a destructor on the content
6368** when it has finished using that result.
6369** ^If the 4th parameter to the sqlite3_result_text* interfaces
6370** or sqlite3_result_blob is the special constant SQLITE_TRANSIENT
6371** then SQLite makes a copy of the result into space obtained
6372** from [sqlite3_malloc()] before it returns.
6373**
6374** ^For the sqlite3_result_text16(), sqlite3_result_text16le(), and
6375** sqlite3_result_text16be() routines, and for sqlite3_result_text64()
6376** when the encoding is not UTF8, if the input UTF16 begins with a
6377** byte-order mark (BOM, U+FEFF) then the BOM is removed from the
6378** string and the rest of the string is interpreted according to the
6379** byte-order specified by the BOM. ^The byte-order specified by
6380** the BOM at the beginning of the text overrides the byte-order
6381** specified by the interface procedure. ^So, for example, if
6382** sqlite3_result_text16le() is invoked with text that begins
6383** with bytes 0xfe, 0xff (a big-endian byte-order mark) then the
6384** first two bytes of input are skipped and the remaining input
6385** is interpreted as UTF16BE text.
6386**
6387** ^For UTF16 input text to the sqlite3_result_text16(),
6388** sqlite3_result_text16be(), sqlite3_result_text16le(), and
6389** sqlite3_result_text64() routines, if the text contains invalid
6390** UTF16 characters, the invalid characters might be converted
6391** into the unicode replacement character, U+FFFD.
6392**
6393** ^The sqlite3_result_value() interface sets the result of
6394** the application-defined function to be a copy of the
6395** [unprotected sqlite3_value] object specified by the 2nd parameter. ^The
6396** sqlite3_result_value() interface makes a copy of the [sqlite3_value]
6397** so that the [sqlite3_value] specified in the parameter may change or
6398** be deallocated after sqlite3_result_value() returns without harm.
6399** ^A [protected sqlite3_value] object may always be used where an
6400** [unprotected sqlite3_value] object is required, so either
6401** kind of [sqlite3_value] object can be used with this interface.
6402**
6403** ^The sqlite3_result_pointer(C,P,T,D) interface sets the result to an
6404** SQL NULL value, just like [sqlite3_result_null(C)], except that it
6405** also associates the host-language pointer P or type T with that
6406** NULL value such that the pointer can be retrieved within an
6407** [application-defined SQL function] using [sqlite3_value_pointer()].
6408** ^If the D parameter is not NULL, then it is a pointer to a destructor
6409** for the P parameter. ^SQLite invokes D with P as its only argument
6410** when SQLite is finished with P. The T parameter should be a static
6411** string and preferably a string literal. The sqlite3_result_pointer()
6412** routine is part of the [pointer passing interface] added for SQLite 3.20.0.
6413**
6414** If these routines are called from within a different thread
6415** than the one containing the application-defined function that received
6416** the [sqlite3_context] pointer, the results are undefined.
6417*/
6418SQLITE_API void sqlite3_result_blob(sqlite3_context*, const void*, int, void(*)(void*));
6419SQLITE_API void sqlite3_result_blob64(sqlite3_context*,const void*,
6420 sqlite3_uint64,void(*)(void*));
6421SQLITE_API void sqlite3_result_double(sqlite3_context*, double);
6422SQLITE_API void sqlite3_result_error(sqlite3_context*, const char*, int);
6423SQLITE_API void sqlite3_result_error16(sqlite3_context*, const void*, int);
6424SQLITE_API void sqlite3_result_error_toobig(sqlite3_context*);
6425SQLITE_API void sqlite3_result_error_nomem(sqlite3_context*);
6426SQLITE_API void sqlite3_result_error_code(sqlite3_context*, int);
6427SQLITE_API void sqlite3_result_int(sqlite3_context*, int);
6428SQLITE_API void sqlite3_result_int64(sqlite3_context*, sqlite3_int64);
6429SQLITE_API void sqlite3_result_null(sqlite3_context*);
6430SQLITE_API void sqlite3_result_text(sqlite3_context*, const char*, int, void(*)(void*));
6431SQLITE_API void sqlite3_result_text64(sqlite3_context*, const char*,sqlite3_uint64,
6432 void(*)(void*), unsigned char encoding);
6433SQLITE_API void sqlite3_result_text16(sqlite3_context*, const void*, int, void(*)(void*));
6434SQLITE_API void sqlite3_result_text16le(sqlite3_context*, const void*, int,void(*)(void*));
6435SQLITE_API void sqlite3_result_text16be(sqlite3_context*, const void*, int,void(*)(void*));
6436SQLITE_API void sqlite3_result_value(sqlite3_context*, sqlite3_value*);
6437SQLITE_API void sqlite3_result_pointer(sqlite3_context*, void*,const char*,void(*)(void*));
6438SQLITE_API void sqlite3_result_zeroblob(sqlite3_context*, int n);
6439SQLITE_API int sqlite3_result_zeroblob64(sqlite3_context*, sqlite3_uint64 n);
6440
6441
6442/*
6443** CAPI3REF: Setting The Subtype Of An SQL Function
6444** METHOD: sqlite3_context
6445**
6446** The sqlite3_result_subtype(C,T) function causes the subtype of
6447** the result from the [application-defined SQL function] with
6448** [sqlite3_context] C to be the value T. Only the lower 8 bits
6449** of the subtype T are preserved in current versions of SQLite;
6450** higher order bits are discarded.
6451** The number of subtype bytes preserved by SQLite might increase
6452** in future releases of SQLite.
6453**
6454** Every [application-defined SQL function] that invokes this interface
6455** should include the [SQLITE_RESULT_SUBTYPE] property in its
6456** text encoding argument when the SQL function is
6457** [sqlite3_create_function|registered]. If the [SQLITE_RESULT_SUBTYPE]
6458** property is omitted from the function that invokes sqlite3_result_subtype(),
6459** then in some cases the sqlite3_result_subtype() might fail to set
6460** the result subtype.
6461**
6462** If SQLite is compiled with -DSQLITE_STRICT_SUBTYPE=1, then any
6463** SQL function that invokes the sqlite3_result_subtype() interface
6464** and that does not have the SQLITE_RESULT_SUBTYPE property will raise
6465** an error. Future versions of SQLite might enable -DSQLITE_STRICT_SUBTYPE=1
6466** by default.
6467*/
6468SQLITE_API void sqlite3_result_subtype(sqlite3_context*,unsigned int);
6469
6470/*
6471** CAPI3REF: Define New Collating Sequences
6472** METHOD: sqlite3
6473**
6474** ^These functions add, remove, or modify a [collation] associated
6475** with the [database connection] specified as the first argument.
6476**
6477** ^The name of the collation is a UTF-8 string
6478** for sqlite3_create_collation() and sqlite3_create_collation_v2()
6479** and a UTF-16 string in native byte order for sqlite3_create_collation16().
6480** ^Collation names that compare equal according to [sqlite3_strnicmp()] are
6481** considered to be the same name.
6482**
6483** ^(The third argument (eTextRep) must be one of the constants:
6484** <ul>
6485** <li> [SQLITE_UTF8],
6486** <li> [SQLITE_UTF16LE],
6487** <li> [SQLITE_UTF16BE],
6488** <li> [SQLITE_UTF16], or
6489** <li> [SQLITE_UTF16_ALIGNED].
6490** </ul>)^
6491** ^The eTextRep argument determines the encoding of strings passed
6492** to the collating function callback, xCompare.
6493** ^The [SQLITE_UTF16] and [SQLITE_UTF16_ALIGNED] values for eTextRep
6494** force strings to be UTF16 with native byte order.
6495** ^The [SQLITE_UTF16_ALIGNED] value for eTextRep forces strings to begin
6496** on an even byte address.
6497**
6498** ^The fourth argument, pArg, is an application data pointer that is passed
6499** through as the first argument to the collating function callback.
6500**
6501** ^The fifth argument, xCompare, is a pointer to the collating function.
6502** ^Multiple collating functions can be registered using the same name but
6503** with different eTextRep parameters and SQLite will use whichever
6504** function requires the least amount of data transformation.
6505** ^If the xCompare argument is NULL then the collating function is
6506** deleted. ^When all collating functions having the same name are deleted,
6507** that collation is no longer usable.
6508**
6509** ^The collating function callback is invoked with a copy of the pArg
6510** application data pointer and with two strings in the encoding specified
6511** by the eTextRep argument. The two integer parameters to the collating
6512** function callback are the length of the two strings, in bytes. The collating
6513** function must return an integer that is negative, zero, or positive
6514** if the first string is less than, equal to, or greater than the second,
6515** respectively. A collating function must always return the same answer
6516** given the same inputs. If two or more collating functions are registered
6517** to the same collation name (using different eTextRep values) then all
6518** must give an equivalent answer when invoked with equivalent strings.
6519** The collating function must obey the following properties for all
6520** strings A, B, and C:
6521**
6522** <ol>
6523** <li> If A==B then B==A.
6524** <li> If A==B and B==C then A==C.
6525** <li> If A<B THEN B>A.
6526** <li> If A<B and B<C then A<C.
6527** </ol>
6528**
6529** If a collating function fails any of the above constraints and that
6530** collating function is registered and used, then the behavior of SQLite
6531** is undefined.
6532**
6533** ^The sqlite3_create_collation_v2() works like sqlite3_create_collation()
6534** with the addition that the xDestroy callback is invoked on pArg when
6535** the collating function is deleted.
6536** ^Collating functions are deleted when they are overridden by later
6537** calls to the collation creation functions or when the
6538** [database connection] is closed using [sqlite3_close()].
6539**
6540** ^The xDestroy callback is <u>not</u> called if the
6541** sqlite3_create_collation_v2() function fails. Applications that invoke
6542** sqlite3_create_collation_v2() with a non-NULL xDestroy argument should
6543** check the return code and dispose of the application data pointer
6544** themselves rather than expecting SQLite to deal with it for them.
6545** This is different from every other SQLite interface. The inconsistency
6546** is unfortunate but cannot be changed without breaking backwards
6547** compatibility.
6548**
6549** See also: [sqlite3_collation_needed()] and [sqlite3_collation_needed16()].
6550*/
6551SQLITE_API int sqlite3_create_collation(
6552 sqlite3*,
6553 const char *zName,
6554 int eTextRep,
6555 void *pArg,
6556 int(*xCompare)(void*,int,const void*,int,const void*)
6557);
6558SQLITE_API int sqlite3_create_collation_v2(
6559 sqlite3*,
6560 const char *zName,
6561 int eTextRep,
6562 void *pArg,
6563 int(*xCompare)(void*,int,const void*,int,const void*),
6564 void(*xDestroy)(void*)
6565);
6566SQLITE_API int sqlite3_create_collation16(
6567 sqlite3*,
6568 const void *zName,
6569 int eTextRep,
6570 void *pArg,
6571 int(*xCompare)(void*,int,const void*,int,const void*)
6572);
6573
6574/*
6575** CAPI3REF: Collation Needed Callbacks
6576** METHOD: sqlite3
6577**
6578** ^To avoid having to register all collation sequences before a database
6579** can be used, a single callback function may be registered with the
6580** [database connection] to be invoked whenever an undefined collation
6581** sequence is required.
6582**
6583** ^If the function is registered using the sqlite3_collation_needed() API,
6584** then it is passed the names of undefined collation sequences as strings
6585** encoded in UTF-8. ^If sqlite3_collation_needed16() is used,
6586** the names are passed as UTF-16 in machine native byte order.
6587** ^A call to either function replaces the existing collation-needed callback.
6588**
6589** ^(When the callback is invoked, the first argument passed is a copy
6590** of the second argument to sqlite3_collation_needed() or
6591** sqlite3_collation_needed16(). The second argument is the database
6592** connection. The third argument is one of [SQLITE_UTF8], [SQLITE_UTF16BE],
6593** or [SQLITE_UTF16LE], indicating the most desirable form of the collation
6594** sequence function required. The fourth parameter is the name of the
6595** required collation sequence.)^
6596**
6597** The callback function should register the desired collation using
6598** [sqlite3_create_collation()], [sqlite3_create_collation16()], or
6599** [sqlite3_create_collation_v2()].
6600*/
6601SQLITE_API int sqlite3_collation_needed(
6602 sqlite3*,
6603 void*,
6604 void(*)(void*,sqlite3*,int eTextRep,const char*)
6605);
6606SQLITE_API int sqlite3_collation_needed16(
6607 sqlite3*,
6608 void*,
6609 void(*)(void*,sqlite3*,int eTextRep,const void*)
6610);
6611
6612#ifdef SQLITE_ENABLE_CEROD
6613/*
6614** Specify the activation key for a CEROD database. Unless
6615** activated, none of the CEROD routines will work.
6616*/
6617SQLITE_API void sqlite3_activate_cerod(
6618 const char *zPassPhrase /* Activation phrase */
6619);
6620#endif
6621
6622/*
6623** CAPI3REF: Suspend Execution For A Short Time
6624**
6625** The sqlite3_sleep() function causes the current thread to suspend execution
6626** for at least a number of milliseconds specified in its parameter.
6627**
6628** If the operating system does not support sleep requests with
6629** millisecond time resolution, then the time will be rounded up to
6630** the nearest second. The number of milliseconds of sleep actually
6631** requested from the operating system is returned.
6632**
6633** ^SQLite implements this interface by calling the xSleep()
6634** method of the default [sqlite3_vfs] object. If the xSleep() method
6635** of the default VFS is not implemented correctly, or not implemented at
6636** all, then the behavior of sqlite3_sleep() may deviate from the description
6637** in the previous paragraphs.
6638**
6639** If a negative argument is passed to sqlite3_sleep() the results vary by
6640** VFS and operating system. Some system treat a negative argument as an
6641** instruction to sleep forever. Others understand it to mean do not sleep
6642** at all. ^In SQLite version 3.42.0 and later, a negative
6643** argument passed into sqlite3_sleep() is changed to zero before it is relayed
6644** down into the xSleep method of the VFS.
6645*/
6646SQLITE_API int sqlite3_sleep(int);
6647
6648/*
6649** CAPI3REF: Name Of The Folder Holding Temporary Files
6650**
6651** ^(If this global variable is made to point to a string which is
6652** the name of a folder (a.k.a. directory), then all temporary files
6653** created by SQLite when using a built-in [sqlite3_vfs | VFS]
6654** will be placed in that directory.)^ ^If this variable
6655** is a NULL pointer, then SQLite performs a search for an appropriate
6656** temporary file directory.
6657**
6658** Applications are strongly discouraged from using this global variable.
6659** It is required to set a temporary folder on Windows Runtime (WinRT).
6660** But for all other platforms, it is highly recommended that applications
6661** neither read nor write this variable. This global variable is a relic
6662** that exists for backwards compatibility of legacy applications and should
6663** be avoided in new projects.
6664**
6665** It is not safe to read or modify this variable in more than one
6666** thread at a time. It is not safe to read or modify this variable
6667** if a [database connection] is being used at the same time in a separate
6668** thread.
6669** It is intended that this variable be set once
6670** as part of process initialization and before any SQLite interface
6671** routines have been called and that this variable remain unchanged
6672** thereafter.
6673**
6674** ^The [temp_store_directory pragma] may modify this variable and cause
6675** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore,
6676** the [temp_store_directory pragma] always assumes that any string
6677** that this variable points to is held in memory obtained from
6678** [sqlite3_malloc] and the pragma may attempt to free that memory
6679** using [sqlite3_free].
6680** Hence, if this variable is modified directly, either it should be
6681** made NULL or made to point to memory obtained from [sqlite3_malloc]
6682** or else the use of the [temp_store_directory pragma] should be avoided.
6683** Except when requested by the [temp_store_directory pragma], SQLite
6684** does not free the memory that sqlite3_temp_directory points to. If
6685** the application wants that memory to be freed, it must do
6686** so itself, taking care to only do so after all [database connection]
6687** objects have been destroyed.
6688**
6689** <b>Note to Windows Runtime users:</b> The temporary directory must be set
6690** prior to calling [sqlite3_open] or [sqlite3_open_v2]. Otherwise, various
6691** features that require the use of temporary files may fail. Here is an
6692** example of how to do this using C++ with the Windows Runtime:
6693**
6694** <blockquote><pre>
6695** LPCWSTR zPath = Windows::Storage::ApplicationData::Current->
6696** TemporaryFolder->Path->Data();
6697** char zPathBuf[MAX_PATH + 1];
6698** memset(zPathBuf, 0, sizeof(zPathBuf));
6699** WideCharToMultiByte(CP_UTF8, 0, zPath, -1, zPathBuf, sizeof(zPathBuf),
6700** NULL, NULL);
6701** sqlite3_temp_directory = sqlite3_mprintf("%s", zPathBuf);
6702** </pre></blockquote>
6703*/
6704SQLITE_API SQLITE_EXTERN char *sqlite3_temp_directory;
6705
6706/*
6707** CAPI3REF: Name Of The Folder Holding Database Files
6708**
6709** ^(If this global variable is made to point to a string which is
6710** the name of a folder (a.k.a. directory), then all database files
6711** specified with a relative pathname and created or accessed by
6712** SQLite when using a built-in windows [sqlite3_vfs | VFS] will be assumed
6713** to be relative to that directory.)^ ^If this variable is a NULL
6714** pointer, then SQLite assumes that all database files specified
6715** with a relative pathname are relative to the current directory
6716** for the process. Only the windows VFS makes use of this global
6717** variable; it is ignored by the unix VFS.
6718**
6719** Changing the value of this variable while a database connection is
6720** open can result in a corrupt database.
6721**
6722** It is not safe to read or modify this variable in more than one
6723** thread at a time. It is not safe to read or modify this variable
6724** if a [database connection] is being used at the same time in a separate
6725** thread.
6726** It is intended that this variable be set once
6727** as part of process initialization and before any SQLite interface
6728** routines have been called and that this variable remain unchanged
6729** thereafter.
6730**
6731** ^The [data_store_directory pragma] may modify this variable and cause
6732** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore,
6733** the [data_store_directory pragma] always assumes that any string
6734** that this variable points to is held in memory obtained from
6735** [sqlite3_malloc] and the pragma may attempt to free that memory
6736** using [sqlite3_free].
6737** Hence, if this variable is modified directly, either it should be
6738** made NULL or made to point to memory obtained from [sqlite3_malloc]
6739** or else the use of the [data_store_directory pragma] should be avoided.
6740*/
6741SQLITE_API SQLITE_EXTERN char *sqlite3_data_directory;
6742
6743/*
6744** CAPI3REF: Win32 Specific Interface
6745**
6746** These interfaces are available only on Windows. The
6747** [sqlite3_win32_set_directory] interface is used to set the value associated
6748** with the [sqlite3_temp_directory] or [sqlite3_data_directory] variable, to
6749** zValue, depending on the value of the type parameter. The zValue parameter
6750** should be NULL to cause the previous value to be freed via [sqlite3_free];
6751** a non-NULL value will be copied into memory obtained from [sqlite3_malloc]
6752** prior to being used. The [sqlite3_win32_set_directory] interface returns
6753** [SQLITE_OK] to indicate success, [SQLITE_ERROR] if the type is unsupported,
6754** or [SQLITE_NOMEM] if memory could not be allocated. The value of the
6755** [sqlite3_data_directory] variable is intended to act as a replacement for
6756** the current directory on the sub-platforms of Win32 where that concept is
6757** not present, e.g. WinRT and UWP. The [sqlite3_win32_set_directory8] and
6758** [sqlite3_win32_set_directory16] interfaces behave exactly the same as the
6759** sqlite3_win32_set_directory interface except the string parameter must be
6760** UTF-8 or UTF-16, respectively.
6761*/
6762SQLITE_API int sqlite3_win32_set_directory(
6763 unsigned long type, /* Identifier for directory being set or reset */
6764 void *zValue /* New value for directory being set or reset */
6765);
6766SQLITE_API int sqlite3_win32_set_directory8(unsigned long type, const char *zValue);
6767SQLITE_API int sqlite3_win32_set_directory16(unsigned long type, const void *zValue);
6768
6769/*
6770** CAPI3REF: Win32 Directory Types
6771**
6772** These macros are only available on Windows. They define the allowed values
6773** for the type argument to the [sqlite3_win32_set_directory] interface.
6774*/
6775#define SQLITE_WIN32_DATA_DIRECTORY_TYPE 1
6776#define SQLITE_WIN32_TEMP_DIRECTORY_TYPE 2
6777
6778/*
6779** CAPI3REF: Test For Auto-Commit Mode
6780** KEYWORDS: {autocommit mode}
6781** METHOD: sqlite3
6782**
6783** ^The sqlite3_get_autocommit() interface returns non-zero or
6784** zero if the given database connection is or is not in autocommit mode,
6785** respectively. ^Autocommit mode is on by default.
6786** ^Autocommit mode is disabled by a [BEGIN] statement.
6787** ^Autocommit mode is re-enabled by a [COMMIT] or [ROLLBACK].
6788**
6789** If certain kinds of errors occur on a statement within a multi-statement
6790** transaction (errors including [SQLITE_FULL], [SQLITE_IOERR],
6791** [SQLITE_NOMEM], [SQLITE_BUSY], and [SQLITE_INTERRUPT]) then the
6792** transaction might be rolled back automatically. The only way to
6793** find out whether SQLite automatically rolled back the transaction after
6794** an error is to use this function.
6795**
6796** If another thread changes the autocommit status of the database
6797** connection while this routine is running, then the return value
6798** is undefined.
6799*/
6800SQLITE_API int sqlite3_get_autocommit(sqlite3*);
6801
6802/*
6803** CAPI3REF: Find The Database Handle Of A Prepared Statement
6804** METHOD: sqlite3_stmt
6805**
6806** ^The sqlite3_db_handle interface returns the [database connection] handle
6807** to which a [prepared statement] belongs. ^The [database connection]
6808** returned by sqlite3_db_handle is the same [database connection]
6809** that was the first argument
6810** to the [sqlite3_prepare_v2()] call (or its variants) that was used to
6811** create the statement in the first place.
6812*/
6813SQLITE_API sqlite3 *sqlite3_db_handle(sqlite3_stmt*);
6814
6815/*
6816** CAPI3REF: Return The Schema Name For A Database Connection
6817** METHOD: sqlite3
6818**
6819** ^The sqlite3_db_name(D,N) interface returns a pointer to the schema name
6820** for the N-th database on database connection D, or a NULL pointer if N is
6821** out of range. An N value of 0 means the main database file. An N of 1 is
6822** the "temp" schema. Larger values of N correspond to various ATTACH-ed
6823** databases.
6824**
6825** Space to hold the string that is returned by sqlite3_db_name() is managed
6826** by SQLite itself. The string might be deallocated by any operation that
6827** changes the schema, including [ATTACH] or [DETACH] or calls to
6828** [sqlite3_serialize()] or [sqlite3_deserialize()], even operations that
6829** occur on a different thread. Applications that need to
6830** remember the string long-term should make their own copy. Applications that
6831** are accessing the same database connection simultaneously on multiple
6832** threads should mutex-protect calls to this API and should make their own
6833** private copy of the result prior to releasing the mutex.
6834*/
6835SQLITE_API const char *sqlite3_db_name(sqlite3 *db, int N);
6836
6837/*
6838** CAPI3REF: Return The Filename For A Database Connection
6839** METHOD: sqlite3
6840**
6841** ^The sqlite3_db_filename(D,N) interface returns a pointer to the filename
6842** associated with database N of connection D.
6843** ^If there is no attached database N on the database
6844** connection D, or if database N is a temporary or in-memory database, then
6845** this function will return either a NULL pointer or an empty string.
6846**
6847** ^The string value returned by this routine is owned and managed by
6848** the database connection. ^The value will be valid until the database N
6849** is [DETACH]-ed or until the database connection closes.
6850**
6851** ^The filename returned by this function is the output of the
6852** xFullPathname method of the [VFS]. ^In other words, the filename
6853** will be an absolute pathname, even if the filename used
6854** to open the database originally was a URI or relative pathname.
6855**
6856** If the filename pointer returned by this routine is not NULL, then it
6857** can be used as the filename input parameter to these routines:
6858** <ul>
6859** <li> [sqlite3_uri_parameter()]
6860** <li> [sqlite3_uri_boolean()]
6861** <li> [sqlite3_uri_int64()]
6862** <li> [sqlite3_filename_database()]
6863** <li> [sqlite3_filename_journal()]
6864** <li> [sqlite3_filename_wal()]
6865** </ul>
6866*/
6867SQLITE_API sqlite3_filename sqlite3_db_filename(sqlite3 *db, const char *zDbName);
6868
6869/*
6870** CAPI3REF: Determine if a database is read-only
6871** METHOD: sqlite3
6872**
6873** ^The sqlite3_db_readonly(D,N) interface returns 1 if the database N
6874** of connection D is read-only, 0 if it is read/write, or -1 if N is not
6875** the name of a database on connection D.
6876*/
6877SQLITE_API int sqlite3_db_readonly(sqlite3 *db, const char *zDbName);
6878
6879/*
6880** CAPI3REF: Determine the transaction state of a database
6881** METHOD: sqlite3
6882**
6883** ^The sqlite3_txn_state(D,S) interface returns the current
6884** [transaction state] of schema S in database connection D. ^If S is NULL,
6885** then the highest transaction state of any schema on database connection D
6886** is returned. Transaction states are (in order of lowest to highest):
6887** <ol>
6888** <li value="0"> SQLITE_TXN_NONE
6889** <li value="1"> SQLITE_TXN_READ
6890** <li value="2"> SQLITE_TXN_WRITE
6891** </ol>
6892** ^If the S argument to sqlite3_txn_state(D,S) is not the name of
6893** a valid schema, then -1 is returned.
6894*/
6895SQLITE_API int sqlite3_txn_state(sqlite3*,const char *zSchema);
6896
6897/*
6898** CAPI3REF: Allowed return values from sqlite3_txn_state()
6899** KEYWORDS: {transaction state}
6900**
6901** These constants define the current transaction state of a database file.
6902** ^The [sqlite3_txn_state(D,S)] interface returns one of these
6903** constants in order to describe the transaction state of schema S
6904** in [database connection] D.
6905**
6906** <dl>
6907** [[SQLITE_TXN_NONE]] <dt>SQLITE_TXN_NONE</dt>
6908** <dd>The SQLITE_TXN_NONE state means that no transaction is currently
6909** pending.</dd>
6910**
6911** [[SQLITE_TXN_READ]] <dt>SQLITE_TXN_READ</dt>
6912** <dd>The SQLITE_TXN_READ state means that the database is currently
6913** in a read transaction. Content has been read from the database file
6914** but nothing in the database file has changed. The transaction state
6915** will be advanced to SQLITE_TXN_WRITE if any changes occur and there are
6916** no other conflicting concurrent write transactions. The transaction
6917** state will revert to SQLITE_TXN_NONE following a [ROLLBACK] or
6918** [COMMIT].</dd>
6919**
6920** [[SQLITE_TXN_WRITE]] <dt>SQLITE_TXN_WRITE</dt>
6921** <dd>The SQLITE_TXN_WRITE state means that the database is currently
6922** in a write transaction. Content has been written to the database file
6923** but has not yet committed. The transaction state will change to
6924** SQLITE_TXN_NONE at the next [ROLLBACK] or [COMMIT].</dd>
6925*/
6926#define SQLITE_TXN_NONE 0
6927#define SQLITE_TXN_READ 1
6928#define SQLITE_TXN_WRITE 2
6929
6930/*
6931** CAPI3REF: Find the next prepared statement
6932** METHOD: sqlite3
6933**
6934** ^This interface returns a pointer to the next [prepared statement] after
6935** pStmt associated with the [database connection] pDb. ^If pStmt is NULL
6936** then this interface returns a pointer to the first prepared statement
6937** associated with the database connection pDb. ^If no prepared statement
6938** satisfies the conditions of this routine, it returns NULL.
6939**
6940** The [database connection] pointer D in a call to
6941** [sqlite3_next_stmt(D,S)] must refer to an open database
6942** connection and in particular must not be a NULL pointer.
6943*/
6944SQLITE_API sqlite3_stmt *sqlite3_next_stmt(sqlite3 *pDb, sqlite3_stmt *pStmt);
6945
6946/*
6947** CAPI3REF: Commit And Rollback Notification Callbacks
6948** METHOD: sqlite3
6949**
6950** ^The sqlite3_commit_hook() interface registers a callback
6951** function to be invoked whenever a transaction is [COMMIT | committed].
6952** ^Any callback set by a previous call to sqlite3_commit_hook()
6953** for the same database connection is overridden.
6954** ^The sqlite3_rollback_hook() interface registers a callback
6955** function to be invoked whenever a transaction is [ROLLBACK | rolled back].
6956** ^Any callback set by a previous call to sqlite3_rollback_hook()
6957** for the same database connection is overridden.
6958** ^The pArg argument is passed through to the callback.
6959** ^If the callback on a commit hook function returns non-zero,
6960** then the commit is converted into a rollback.
6961**
6962** ^The sqlite3_commit_hook(D,C,P) and sqlite3_rollback_hook(D,C,P) functions
6963** return the P argument from the previous call of the same function
6964** on the same [database connection] D, or NULL for
6965** the first call for each function on D.
6966**
6967** The commit and rollback hook callbacks are not reentrant.
6968** The callback implementation must not do anything that will modify
6969** the database connection that invoked the callback. Any actions
6970** to modify the database connection must be deferred until after the
6971** completion of the [sqlite3_step()] call that triggered the commit
6972** or rollback hook in the first place.
6973** Note that running any other SQL statements, including SELECT statements,
6974** or merely calling [sqlite3_prepare_v2()] and [sqlite3_step()] will modify
6975** the database connections for the meaning of "modify" in this paragraph.
6976**
6977** ^Registering a NULL function disables the callback.
6978**
6979** ^When the commit hook callback routine returns zero, the [COMMIT]
6980** operation is allowed to continue normally. ^If the commit hook
6981** returns non-zero, then the [COMMIT] is converted into a [ROLLBACK].
6982** ^The rollback hook is invoked on a rollback that results from a commit
6983** hook returning non-zero, just as it would be with any other rollback.
6984**
6985** ^For the purposes of this API, a transaction is said to have been
6986** rolled back if an explicit "ROLLBACK" statement is executed, or
6987** an error or constraint causes an implicit rollback to occur.
6988** ^The rollback callback is not invoked if a transaction is
6989** automatically rolled back because the database connection is closed.
6990**
6991** See also the [sqlite3_update_hook()] interface.
6992*/
6993SQLITE_API void *sqlite3_commit_hook(sqlite3*, int(*)(void*), void*);
6994SQLITE_API void *sqlite3_rollback_hook(sqlite3*, void(*)(void *), void*);
6995
6996/*
6997** CAPI3REF: Autovacuum Compaction Amount Callback
6998** METHOD: sqlite3
6999**
7000** ^The sqlite3_autovacuum_pages(D,C,P,X) interface registers a callback
7001** function C that is invoked prior to each autovacuum of the database
7002** file. ^The callback is passed a copy of the generic data pointer (P),
7003** the schema-name of the attached database that is being autovacuumed,
7004** the size of the database file in pages, the number of free pages,
7005** and the number of bytes per page, respectively. The callback should
7006** return the number of free pages that should be removed by the
7007** autovacuum. ^If the callback returns zero, then no autovacuum happens.
7008** ^If the value returned is greater than or equal to the number of
7009** free pages, then a complete autovacuum happens.
7010**
7011** <p>^If there are multiple ATTACH-ed database files that are being
7012** modified as part of a transaction commit, then the autovacuum pages
7013** callback is invoked separately for each file.
7014**
7015** <p><b>The callback is not reentrant.</b> The callback function should
7016** not attempt to invoke any other SQLite interface. If it does, bad
7017** things may happen, including segmentation faults and corrupt database
7018** files. The callback function should be a simple function that
7019** does some arithmetic on its input parameters and returns a result.
7020**
7021** ^The X parameter to sqlite3_autovacuum_pages(D,C,P,X) is an optional
7022** destructor for the P parameter. ^If X is not NULL, then X(P) is
7023** invoked whenever the database connection closes or when the callback
7024** is overwritten by another invocation of sqlite3_autovacuum_pages().
7025**
7026** <p>^There is only one autovacuum pages callback per database connection.
7027** ^Each call to the sqlite3_autovacuum_pages() interface overrides all
7028** previous invocations for that database connection. ^If the callback
7029** argument (C) to sqlite3_autovacuum_pages(D,C,P,X) is a NULL pointer,
7030** then the autovacuum steps callback is canceled. The return value
7031** from sqlite3_autovacuum_pages() is normally SQLITE_OK, but might
7032** be some other error code if something goes wrong. The current
7033** implementation will only return SQLITE_OK or SQLITE_MISUSE, but other
7034** return codes might be added in future releases.
7035**
7036** <p>If no autovacuum pages callback is specified (the usual case) or
7037** a NULL pointer is provided for the callback,
7038** then the default behavior is to vacuum all free pages. So, in other
7039** words, the default behavior is the same as if the callback function
7040** were something like this:
7041**
7042** <blockquote><pre>
7043** unsigned int demonstration_autovac_pages_callback(
7044** void *pClientData,
7045** const char *zSchema,
7046** unsigned int nDbPage,
7047** unsigned int nFreePage,
7048** unsigned int nBytePerPage
7049** ){
7050** return nFreePage;
7051** }
7052** </pre></blockquote>
7053*/
7054SQLITE_API int sqlite3_autovacuum_pages(
7055 sqlite3 *db,
7056 unsigned int(*)(void*,const char*,unsigned int,unsigned int,unsigned int),
7057 void*,
7058 void(*)(void*)
7059);
7060
7061
7062/*
7063** CAPI3REF: Data Change Notification Callbacks
7064** METHOD: sqlite3
7065**
7066** ^The sqlite3_update_hook() interface registers a callback function
7067** with the [database connection] identified by the first argument
7068** to be invoked whenever a row is updated, inserted or deleted in
7069** a [rowid table].
7070** ^Any callback set by a previous call to this function
7071** for the same database connection is overridden.
7072**
7073** ^The second argument is a pointer to the function to invoke when a
7074** row is updated, inserted or deleted in a rowid table.
7075** ^The update hook is disabled by invoking sqlite3_update_hook()
7076** with a NULL pointer as the second parameter.
7077** ^The first argument to the callback is a copy of the third argument
7078** to sqlite3_update_hook().
7079** ^The second callback argument is one of [SQLITE_INSERT], [SQLITE_DELETE],
7080** or [SQLITE_UPDATE], depending on the operation that caused the callback
7081** to be invoked.
7082** ^The third and fourth arguments to the callback contain pointers to the
7083** database and table name containing the affected row.
7084** ^The final callback parameter is the [rowid] of the row.
7085** ^In the case of an update, this is the [rowid] after the update takes place.
7086**
7087** ^(The update hook is not invoked when internal system tables are
7088** modified (i.e. sqlite_sequence).)^
7089** ^The update hook is not invoked when [WITHOUT ROWID] tables are modified.
7090**
7091** ^In the current implementation, the update hook
7092** is not invoked when conflicting rows are deleted because of an
7093** [ON CONFLICT | ON CONFLICT REPLACE] clause. ^Nor is the update hook
7094** invoked when rows are deleted using the [truncate optimization].
7095** The exceptions defined in this paragraph might change in a future
7096** release of SQLite.
7097**
7098** Whether the update hook is invoked before or after the
7099** corresponding change is currently unspecified and may differ
7100** depending on the type of change. Do not rely on the order of the
7101** hook call with regards to the final result of the operation which
7102** triggers the hook.
7103**
7104** The update hook implementation must not do anything that will modify
7105** the database connection that invoked the update hook. Any actions
7106** to modify the database connection must be deferred until after the
7107** completion of the [sqlite3_step()] call that triggered the update hook.
7108** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their
7109** database connections for the meaning of "modify" in this paragraph.
7110**
7111** ^The sqlite3_update_hook(D,C,P) function
7112** returns the P argument from the previous call
7113** on the same [database connection] D, or NULL for
7114** the first call on D.
7115**
7116** See also the [sqlite3_commit_hook()], [sqlite3_rollback_hook()],
7117** and [sqlite3_preupdate_hook()] interfaces.
7118*/
7119SQLITE_API void *sqlite3_update_hook(
7120 sqlite3*,
7121 void(*)(void *,int ,char const *,char const *,sqlite3_int64),
7122 void*
7123);
7124
7125/*
7126** CAPI3REF: Enable Or Disable Shared Pager Cache
7127**
7128** ^(This routine enables or disables the sharing of the database cache
7129** and schema data structures between [database connection | connections]
7130** to the same database. Sharing is enabled if the argument is true
7131** and disabled if the argument is false.)^
7132**
7133** This interface is omitted if SQLite is compiled with
7134** [-DSQLITE_OMIT_SHARED_CACHE]. The [-DSQLITE_OMIT_SHARED_CACHE]
7135** compile-time option is recommended because the
7136** [use of shared cache mode is discouraged].
7137**
7138** ^Cache sharing is enabled and disabled for an entire process.
7139** This is a change as of SQLite [version 3.5.0] ([dateof:3.5.0]).
7140** In prior versions of SQLite,
7141** sharing was enabled or disabled for each thread separately.
7142**
7143** ^(The cache sharing mode set by this interface effects all subsequent
7144** calls to [sqlite3_open()], [sqlite3_open_v2()], and [sqlite3_open16()].
7145** Existing database connections continue to use the sharing mode
7146** that was in effect at the time they were opened.)^
7147**
7148** ^(This routine returns [SQLITE_OK] if shared cache was enabled or disabled
7149** successfully. An [error code] is returned otherwise.)^
7150**
7151** ^Shared cache is disabled by default. It is recommended that it stay
7152** that way. In other words, do not use this routine. This interface
7153** continues to be provided for historical compatibility, but its use is
7154** discouraged. Any use of shared cache is discouraged. If shared cache
7155** must be used, it is recommended that shared cache only be enabled for
7156** individual database connections using the [sqlite3_open_v2()] interface
7157** with the [SQLITE_OPEN_SHAREDCACHE] flag.
7158**
7159** Note: This method is disabled on MacOS X 10.7 and iOS version 5.0
7160** and will always return SQLITE_MISUSE. On those systems,
7161** shared cache mode should be enabled per-database connection via
7162** [sqlite3_open_v2()] with [SQLITE_OPEN_SHAREDCACHE].
7163**
7164** This interface is threadsafe on processors where writing a
7165** 32-bit integer is atomic.
7166**
7167** See Also: [SQLite Shared-Cache Mode]
7168*/
7169SQLITE_API int sqlite3_enable_shared_cache(int);
7170
7171/*
7172** CAPI3REF: Attempt To Free Heap Memory
7173**
7174** ^The sqlite3_release_memory() interface attempts to free N bytes
7175** of heap memory by deallocating non-essential memory allocations
7176** held by the database library. Memory used to cache database
7177** pages to improve performance is an example of non-essential memory.
7178** ^sqlite3_release_memory() returns the number of bytes actually freed,
7179** which might be more or less than the amount requested.
7180** ^The sqlite3_release_memory() routine is a no-op returning zero
7181** if SQLite is not compiled with [SQLITE_ENABLE_MEMORY_MANAGEMENT].
7182**
7183** See also: [sqlite3_db_release_memory()]
7184*/
7185SQLITE_API int sqlite3_release_memory(int);
7186
7187/*
7188** CAPI3REF: Free Memory Used By A Database Connection
7189** METHOD: sqlite3
7190**
7191** ^The sqlite3_db_release_memory(D) interface attempts to free as much heap
7192** memory as possible from database connection D. Unlike the
7193** [sqlite3_release_memory()] interface, this interface is in effect even
7194** when the [SQLITE_ENABLE_MEMORY_MANAGEMENT] compile-time option is
7195** omitted.
7196**
7197** See also: [sqlite3_release_memory()]
7198*/
7199SQLITE_API int sqlite3_db_release_memory(sqlite3*);
7200
7201/*
7202** CAPI3REF: Impose A Limit On Heap Size
7203**
7204** These interfaces impose limits on the amount of heap memory that will be
7205** used by all database connections within a single process.
7206**
7207** ^The sqlite3_soft_heap_limit64() interface sets and/or queries the
7208** soft limit on the amount of heap memory that may be allocated by SQLite.
7209** ^SQLite strives to keep heap memory utilization below the soft heap
7210** limit by reducing the number of pages held in the page cache
7211** as heap memory usages approaches the limit.
7212** ^The soft heap limit is "soft" because even though SQLite strives to stay
7213** below the limit, it will exceed the limit rather than generate
7214** an [SQLITE_NOMEM] error. In other words, the soft heap limit
7215** is advisory only.
7216**
7217** ^The sqlite3_hard_heap_limit64(N) interface sets a hard upper bound of
7218** N bytes on the amount of memory that will be allocated. ^The
7219** sqlite3_hard_heap_limit64(N) interface is similar to
7220** sqlite3_soft_heap_limit64(N) except that memory allocations will fail
7221** when the hard heap limit is reached.
7222**
7223** ^The return value from both sqlite3_soft_heap_limit64() and
7224** sqlite3_hard_heap_limit64() is the size of
7225** the heap limit prior to the call, or negative in the case of an
7226** error. ^If the argument N is negative
7227** then no change is made to the heap limit. Hence, the current
7228** size of heap limits can be determined by invoking
7229** sqlite3_soft_heap_limit64(-1) or sqlite3_hard_heap_limit(-1).
7230**
7231** ^Setting the heap limits to zero disables the heap limiter mechanism.
7232**
7233** ^The soft heap limit may not be greater than the hard heap limit.
7234** ^If the hard heap limit is enabled and if sqlite3_soft_heap_limit(N)
7235** is invoked with a value of N that is greater than the hard heap limit,
7236** the soft heap limit is set to the value of the hard heap limit.
7237** ^The soft heap limit is automatically enabled whenever the hard heap
7238** limit is enabled. ^When sqlite3_hard_heap_limit64(N) is invoked and
7239** the soft heap limit is outside the range of 1..N, then the soft heap
7240** limit is set to N. ^Invoking sqlite3_soft_heap_limit64(0) when the
7241** hard heap limit is enabled makes the soft heap limit equal to the
7242** hard heap limit.
7243**
7244** The memory allocation limits can also be adjusted using
7245** [PRAGMA soft_heap_limit] and [PRAGMA hard_heap_limit].
7246**
7247** ^(The heap limits are not enforced in the current implementation
7248** if one or more of following conditions are true:
7249**
7250** <ul>
7251** <li> The limit value is set to zero.
7252** <li> Memory accounting is disabled using a combination of the
7253** [sqlite3_config]([SQLITE_CONFIG_MEMSTATUS],...) start-time option and
7254** the [SQLITE_DEFAULT_MEMSTATUS] compile-time option.
7255** <li> An alternative page cache implementation is specified using
7256** [sqlite3_config]([SQLITE_CONFIG_PCACHE2],...).
7257** <li> The page cache allocates from its own memory pool supplied
7258** by [sqlite3_config]([SQLITE_CONFIG_PAGECACHE],...) rather than
7259** from the heap.
7260** </ul>)^
7261**
7262** The circumstances under which SQLite will enforce the heap limits may
7263** change in future releases of SQLite.
7264*/
7265SQLITE_API sqlite3_int64 sqlite3_soft_heap_limit64(sqlite3_int64 N);
7266SQLITE_API sqlite3_int64 sqlite3_hard_heap_limit64(sqlite3_int64 N);
7267
7268/*
7269** CAPI3REF: Deprecated Soft Heap Limit Interface
7270** DEPRECATED
7271**
7272** This is a deprecated version of the [sqlite3_soft_heap_limit64()]
7273** interface. This routine is provided for historical compatibility
7274** only. All new applications should use the
7275** [sqlite3_soft_heap_limit64()] interface rather than this one.
7276*/
7277SQLITE_API SQLITE_DEPRECATED void sqlite3_soft_heap_limit(int N);
7278
7279
7280/*
7281** CAPI3REF: Extract Metadata About A Column Of A Table
7282** METHOD: sqlite3
7283**
7284** ^(The sqlite3_table_column_metadata(X,D,T,C,....) routine returns
7285** information about column C of table T in database D
7286** on [database connection] X.)^ ^The sqlite3_table_column_metadata()
7287** interface returns SQLITE_OK and fills in the non-NULL pointers in
7288** the final five arguments with appropriate values if the specified
7289** column exists. ^The sqlite3_table_column_metadata() interface returns
7290** SQLITE_ERROR if the specified column does not exist.
7291** ^If the column-name parameter to sqlite3_table_column_metadata() is a
7292** NULL pointer, then this routine simply checks for the existence of the
7293** table and returns SQLITE_OK if the table exists and SQLITE_ERROR if it
7294** does not. If the table name parameter T in a call to
7295** sqlite3_table_column_metadata(X,D,T,C,...) is NULL then the result is
7296** undefined behavior.
7297**
7298** ^The column is identified by the second, third and fourth parameters to
7299** this function. ^(The second parameter is either the name of the database
7300** (i.e. "main", "temp", or an attached database) containing the specified
7301** table or NULL.)^ ^If it is NULL, then all attached databases are searched
7302** for the table using the same algorithm used by the database engine to
7303** resolve unqualified table references.
7304**
7305** ^The third and fourth parameters to this function are the table and column
7306** name of the desired column, respectively.
7307**
7308** ^Metadata is returned by writing to the memory locations passed as the 5th
7309** and subsequent parameters to this function. ^Any of these arguments may be
7310** NULL, in which case the corresponding element of metadata is omitted.
7311**
7312** ^(<blockquote>
7313** <table border="1">
7314** <tr><th> Parameter <th> Output<br>Type <th> Description
7315**
7316** <tr><td> 5th <td> const char* <td> Data type
7317** <tr><td> 6th <td> const char* <td> Name of default collation sequence
7318** <tr><td> 7th <td> int <td> True if column has a NOT NULL constraint
7319** <tr><td> 8th <td> int <td> True if column is part of the PRIMARY KEY
7320** <tr><td> 9th <td> int <td> True if column is [AUTOINCREMENT]
7321** </table>
7322** </blockquote>)^
7323**
7324** ^The memory pointed to by the character pointers returned for the
7325** declaration type and collation sequence is valid until the next
7326** call to any SQLite API function.
7327**
7328** ^If the specified table is actually a view, an [error code] is returned.
7329**
7330** ^If the specified column is "rowid", "oid" or "_rowid_" and the table
7331** is not a [WITHOUT ROWID] table and an
7332** [INTEGER PRIMARY KEY] column has been explicitly declared, then the output
7333** parameters are set for the explicitly declared column. ^(If there is no
7334** [INTEGER PRIMARY KEY] column, then the outputs
7335** for the [rowid] are set as follows:
7336**
7337** <pre>
7338** data type: "INTEGER"
7339** collation sequence: "BINARY"
7340** not null: 0
7341** primary key: 1
7342** auto increment: 0
7343** </pre>)^
7344**
7345** ^This function causes all database schemas to be read from disk and
7346** parsed, if that has not already been done, and returns an error if
7347** any errors are encountered while loading the schema.
7348*/
7349SQLITE_API int sqlite3_table_column_metadata(
7350 sqlite3 *db, /* Connection handle */
7351 const char *zDbName, /* Database name or NULL */
7352 const char *zTableName, /* Table name */
7353 const char *zColumnName, /* Column name */
7354 char const **pzDataType, /* OUTPUT: Declared data type */
7355 char const **pzCollSeq, /* OUTPUT: Collation sequence name */
7356 int *pNotNull, /* OUTPUT: True if NOT NULL constraint exists */
7357 int *pPrimaryKey, /* OUTPUT: True if column part of PK */
7358 int *pAutoinc /* OUTPUT: True if column is auto-increment */
7359);
7360
7361/*
7362** CAPI3REF: Load An Extension
7363** METHOD: sqlite3
7364**
7365** ^This interface loads an SQLite extension library from the named file.
7366**
7367** ^The sqlite3_load_extension() interface attempts to load an
7368** [SQLite extension] library contained in the file zFile. If
7369** the file cannot be loaded directly, attempts are made to load
7370** with various operating-system specific extensions added.
7371** So for example, if "samplelib" cannot be loaded, then names like
7372** "samplelib.so" or "samplelib.dylib" or "samplelib.dll" might
7373** be tried also.
7374**
7375** ^The entry point is zProc.
7376** ^(zProc may be 0, in which case SQLite will try to come up with an
7377** entry point name on its own. It first tries "sqlite3_extension_init".
7378** If that does not work, it constructs a name "sqlite3_X_init" where
7379** X consists of the lower-case equivalent of all ASCII alphabetic
7380** characters in the filename from the last "/" to the first following
7381** "." and omitting any initial "lib".)^
7382** ^The sqlite3_load_extension() interface returns
7383** [SQLITE_OK] on success and [SQLITE_ERROR] if something goes wrong.
7384** ^If an error occurs and pzErrMsg is not 0, then the
7385** [sqlite3_load_extension()] interface shall attempt to
7386** fill *pzErrMsg with error message text stored in memory
7387** obtained from [sqlite3_malloc()]. The calling function
7388** should free this memory by calling [sqlite3_free()].
7389**
7390** ^Extension loading must be enabled using
7391** [sqlite3_enable_load_extension()] or
7392** [sqlite3_db_config](db,[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION],1,NULL)
7393** prior to calling this API,
7394** otherwise an error will be returned.
7395**
7396** <b>Security warning:</b> It is recommended that the
7397** [SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION] method be used to enable only this
7398** interface. The use of the [sqlite3_enable_load_extension()] interface
7399** should be avoided. This will keep the SQL function [load_extension()]
7400** disabled and prevent SQL injections from giving attackers
7401** access to extension loading capabilities.
7402**
7403** See also the [load_extension() SQL function].
7404*/
7405SQLITE_API int sqlite3_load_extension(
7406 sqlite3 *db, /* Load the extension into this database connection */
7407 const char *zFile, /* Name of the shared library containing extension */
7408 const char *zProc, /* Entry point. Derived from zFile if 0 */
7409 char **pzErrMsg /* Put error message here if not 0 */
7410);
7411
7412/*
7413** CAPI3REF: Enable Or Disable Extension Loading
7414** METHOD: sqlite3
7415**
7416** ^So as not to open security holes in older applications that are
7417** unprepared to deal with [extension loading], and as a means of disabling
7418** [extension loading] while evaluating user-entered SQL, the following API
7419** is provided to turn the [sqlite3_load_extension()] mechanism on and off.
7420**
7421** ^Extension loading is off by default.
7422** ^Call the sqlite3_enable_load_extension() routine with onoff==1
7423** to turn extension loading on and call it with onoff==0 to turn
7424** it back off again.
7425**
7426** ^This interface enables or disables both the C-API
7427** [sqlite3_load_extension()] and the SQL function [load_extension()].
7428** ^(Use [sqlite3_db_config](db,[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION],..)
7429** to enable or disable only the C-API.)^
7430**
7431** <b>Security warning:</b> It is recommended that extension loading
7432** be enabled using the [SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION] method
7433** rather than this interface, so the [load_extension()] SQL function
7434** remains disabled. This will prevent SQL injections from giving attackers
7435** access to extension loading capabilities.
7436*/
7437SQLITE_API int sqlite3_enable_load_extension(sqlite3 *db, int onoff);
7438
7439/*
7440** CAPI3REF: Automatically Load Statically Linked Extensions
7441**
7442** ^This interface causes the xEntryPoint() function to be invoked for
7443** each new [database connection] that is created. The idea here is that
7444** xEntryPoint() is the entry point for a statically linked [SQLite extension]
7445** that is to be automatically loaded into all new database connections.
7446**
7447** ^(Even though the function prototype shows that xEntryPoint() takes
7448** no arguments and returns void, SQLite invokes xEntryPoint() with three
7449** arguments and expects an integer result as if the signature of the
7450** entry point were as follows:
7451**
7452** <blockquote><pre>
7453** int xEntryPoint(
7454** sqlite3 *db,
7455** const char **pzErrMsg,
7456** const struct sqlite3_api_routines *pThunk
7457** );
7458** </pre></blockquote>)^
7459**
7460** If the xEntryPoint routine encounters an error, it should make *pzErrMsg
7461** point to an appropriate error message (obtained from [sqlite3_mprintf()])
7462** and return an appropriate [error code]. ^SQLite ensures that *pzErrMsg
7463** is NULL before calling the xEntryPoint(). ^SQLite will invoke
7464** [sqlite3_free()] on *pzErrMsg after xEntryPoint() returns. ^If any
7465** xEntryPoint() returns an error, the [sqlite3_open()], [sqlite3_open16()],
7466** or [sqlite3_open_v2()] call that provoked the xEntryPoint() will fail.
7467**
7468** ^Calling sqlite3_auto_extension(X) with an entry point X that is already
7469** on the list of automatic extensions is a harmless no-op. ^No entry point
7470** will be called more than once for each database connection that is opened.
7471**
7472** See also: [sqlite3_reset_auto_extension()]
7473** and [sqlite3_cancel_auto_extension()]
7474*/
7475SQLITE_API int sqlite3_auto_extension(void(*xEntryPoint)(void));
7476
7477/*
7478** CAPI3REF: Cancel Automatic Extension Loading
7479**
7480** ^The [sqlite3_cancel_auto_extension(X)] interface unregisters the
7481** initialization routine X that was registered using a prior call to
7482** [sqlite3_auto_extension(X)]. ^The [sqlite3_cancel_auto_extension(X)]
7483** routine returns 1 if initialization routine X was successfully
7484** unregistered and it returns 0 if X was not on the list of initialization
7485** routines.
7486*/
7487SQLITE_API int sqlite3_cancel_auto_extension(void(*xEntryPoint)(void));
7488
7489/*
7490** CAPI3REF: Reset Automatic Extension Loading
7491**
7492** ^This interface disables all automatic extensions previously
7493** registered using [sqlite3_auto_extension()].
7494*/
7495SQLITE_API void sqlite3_reset_auto_extension(void);
7496
7497/*
7498** Structures used by the virtual table interface
7499*/
7500typedef struct sqlite3_vtab sqlite3_vtab;
7501typedef struct sqlite3_index_info sqlite3_index_info;
7502typedef struct sqlite3_vtab_cursor sqlite3_vtab_cursor;
7503typedef struct sqlite3_module sqlite3_module;
7504
7505/*
7506** CAPI3REF: Virtual Table Object
7507** KEYWORDS: sqlite3_module {virtual table module}
7508**
7509** This structure, sometimes called a "virtual table module",
7510** defines the implementation of a [virtual table].
7511** This structure consists mostly of methods for the module.
7512**
7513** ^A virtual table module is created by filling in a persistent
7514** instance of this structure and passing a pointer to that instance
7515** to [sqlite3_create_module()] or [sqlite3_create_module_v2()].
7516** ^The registration remains valid until it is replaced by a different
7517** module or until the [database connection] closes. The content
7518** of this structure must not change while it is registered with
7519** any database connection.
7520*/
7521struct sqlite3_module {
7522 int iVersion;
7523 int (*xCreate)(sqlite3*, void *pAux,
7524 int argc, const char *const*argv,
7525 sqlite3_vtab **ppVTab, char**);
7526 int (*xConnect)(sqlite3*, void *pAux,
7527 int argc, const char *const*argv,
7528 sqlite3_vtab **ppVTab, char**);
7529 int (*xBestIndex)(sqlite3_vtab *pVTab, sqlite3_index_info*);
7530 int (*xDisconnect)(sqlite3_vtab *pVTab);
7531 int (*xDestroy)(sqlite3_vtab *pVTab);
7532 int (*xOpen)(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor);
7533 int (*xClose)(sqlite3_vtab_cursor*);
7534 int (*xFilter)(sqlite3_vtab_cursor*, int idxNum, const char *idxStr,
7535 int argc, sqlite3_value **argv);
7536 int (*xNext)(sqlite3_vtab_cursor*);
7537 int (*xEof)(sqlite3_vtab_cursor*);
7538 int (*xColumn)(sqlite3_vtab_cursor*, sqlite3_context*, int);
7539 int (*xRowid)(sqlite3_vtab_cursor*, sqlite3_int64 *pRowid);
7540 int (*xUpdate)(sqlite3_vtab *, int, sqlite3_value **, sqlite3_int64 *);
7541 int (*xBegin)(sqlite3_vtab *pVTab);
7542 int (*xSync)(sqlite3_vtab *pVTab);
7543 int (*xCommit)(sqlite3_vtab *pVTab);
7544 int (*xRollback)(sqlite3_vtab *pVTab);
7545 int (*xFindFunction)(sqlite3_vtab *pVtab, int nArg, const char *zName,
7546 void (**pxFunc)(sqlite3_context*,int,sqlite3_value**),
7547 void **ppArg);
7548 int (*xRename)(sqlite3_vtab *pVtab, const char *zNew);
7549 /* The methods above are in version 1 of the sqlite_module object. Those
7550 ** below are for version 2 and greater. */
7551 int (*xSavepoint)(sqlite3_vtab *pVTab, int);
7552 int (*xRelease)(sqlite3_vtab *pVTab, int);
7553 int (*xRollbackTo)(sqlite3_vtab *pVTab, int);
7554 /* The methods above are in versions 1 and 2 of the sqlite_module object.
7555 ** Those below are for version 3 and greater. */
7556 int (*xShadowName)(const char*);
7557 /* The methods above are in versions 1 through 3 of the sqlite_module object.
7558 ** Those below are for version 4 and greater. */
7559 int (*xIntegrity)(sqlite3_vtab *pVTab, const char *zSchema,
7560 const char *zTabName, int mFlags, char **pzErr);
7561};
7562
7563/*
7564** CAPI3REF: Virtual Table Indexing Information
7565** KEYWORDS: sqlite3_index_info
7566**
7567** The sqlite3_index_info structure and its substructures is used as part
7568** of the [virtual table] interface to
7569** pass information into and receive the reply from the [xBestIndex]
7570** method of a [virtual table module]. The fields under **Inputs** are the
7571** inputs to xBestIndex and are read-only. xBestIndex inserts its
7572** results into the **Outputs** fields.
7573**
7574** ^(The aConstraint[] array records WHERE clause constraints of the form:
7575**
7576** <blockquote>column OP expr</blockquote>
7577**
7578** where OP is =, <, <=, >, or >=.)^ ^(The particular operator is
7579** stored in aConstraint[].op using one of the
7580** [SQLITE_INDEX_CONSTRAINT_EQ | SQLITE_INDEX_CONSTRAINT_ values].)^
7581** ^(The index of the column is stored in
7582** aConstraint[].iColumn.)^ ^(aConstraint[].usable is TRUE if the
7583** expr on the right-hand side can be evaluated (and thus the constraint
7584** is usable) and false if it cannot.)^
7585**
7586** ^The optimizer automatically inverts terms of the form "expr OP column"
7587** and makes other simplifications to the WHERE clause in an attempt to
7588** get as many WHERE clause terms into the form shown above as possible.
7589** ^The aConstraint[] array only reports WHERE clause terms that are
7590** relevant to the particular virtual table being queried.
7591**
7592** ^Information about the ORDER BY clause is stored in aOrderBy[].
7593** ^Each term of aOrderBy records a column of the ORDER BY clause.
7594**
7595** The colUsed field indicates which columns of the virtual table may be
7596** required by the current scan. Virtual table columns are numbered from
7597** zero in the order in which they appear within the CREATE TABLE statement
7598** passed to sqlite3_declare_vtab(). For the first 63 columns (columns 0-62),
7599** the corresponding bit is set within the colUsed mask if the column may be
7600** required by SQLite. If the table has at least 64 columns and any column
7601** to the right of the first 63 is required, then bit 63 of colUsed is also
7602** set. In other words, column iCol may be required if the expression
7603** (colUsed & ((sqlite3_uint64)1 << (iCol>=63 ? 63 : iCol))) evaluates to
7604** non-zero.
7605**
7606** The [xBestIndex] method must fill aConstraintUsage[] with information
7607** about what parameters to pass to xFilter. ^If argvIndex>0 then
7608** the right-hand side of the corresponding aConstraint[] is evaluated
7609** and becomes the argvIndex-th entry in argv. ^(If aConstraintUsage[].omit
7610** is true, then the constraint is assumed to be fully handled by the
7611** virtual table and might not be checked again by the byte code.)^ ^(The
7612** aConstraintUsage[].omit flag is an optimization hint. When the omit flag
7613** is left in its default setting of false, the constraint will always be
7614** checked separately in byte code. If the omit flag is changed to true, then
7615** the constraint may or may not be checked in byte code. In other words,
7616** when the omit flag is true there is no guarantee that the constraint will
7617** not be checked again using byte code.)^
7618**
7619** ^The idxNum and idxStr values are recorded and passed into the
7620** [xFilter] method.
7621** ^[sqlite3_free()] is used to free idxStr if and only if
7622** needToFreeIdxStr is true.
7623**
7624** ^The orderByConsumed means that output from [xFilter]/[xNext] will occur in
7625** the correct order to satisfy the ORDER BY clause so that no separate
7626** sorting step is required.
7627**
7628** ^The estimatedCost value is an estimate of the cost of a particular
7629** strategy. A cost of N indicates that the cost of the strategy is similar
7630** to a linear scan of an SQLite table with N rows. A cost of log(N)
7631** indicates that the expense of the operation is similar to that of a
7632** binary search on a unique indexed field of an SQLite table with N rows.
7633**
7634** ^The estimatedRows value is an estimate of the number of rows that
7635** will be returned by the strategy.
7636**
7637** The xBestIndex method may optionally populate the idxFlags field with a
7638** mask of SQLITE_INDEX_SCAN_* flags. One such flag is
7639** [SQLITE_INDEX_SCAN_HEX], which if set causes the [EXPLAIN QUERY PLAN]
7640** output to show the idxNum as hex instead of as decimal. Another flag is
7641** SQLITE_INDEX_SCAN_UNIQUE, which if set indicates that the query plan will
7642** return at most one row.
7643**
7644** Additionally, if xBestIndex sets the SQLITE_INDEX_SCAN_UNIQUE flag, then
7645** SQLite also assumes that if a call to the xUpdate() method is made as
7646** part of the same statement to delete or update a virtual table row and the
7647** implementation returns SQLITE_CONSTRAINT, then there is no need to rollback
7648** any database changes. In other words, if the xUpdate() returns
7649** SQLITE_CONSTRAINT, the database contents must be exactly as they were
7650** before xUpdate was called. By contrast, if SQLITE_INDEX_SCAN_UNIQUE is not
7651** set and xUpdate returns SQLITE_CONSTRAINT, any database changes made by
7652** the xUpdate method are automatically rolled back by SQLite.
7653**
7654** IMPORTANT: The estimatedRows field was added to the sqlite3_index_info
7655** structure for SQLite [version 3.8.2] ([dateof:3.8.2]).
7656** If a virtual table extension is
7657** used with an SQLite version earlier than 3.8.2, the results of attempting
7658** to read or write the estimatedRows field are undefined (but are likely
7659** to include crashing the application). The estimatedRows field should
7660** therefore only be used if [sqlite3_libversion_number()] returns a
7661** value greater than or equal to 3008002. Similarly, the idxFlags field
7662** was added for [version 3.9.0] ([dateof:3.9.0]).
7663** It may therefore only be used if
7664** sqlite3_libversion_number() returns a value greater than or equal to
7665** 3009000.
7666*/
7667struct sqlite3_index_info {
7668 /* Inputs */
7669 int nConstraint; /* Number of entries in aConstraint */
7670 struct sqlite3_index_constraint {
7671 int iColumn; /* Column constrained. -1 for ROWID */
7672 unsigned char op; /* Constraint operator */
7673 unsigned char usable; /* True if this constraint is usable */
7674 int iTermOffset; /* Used internally - xBestIndex should ignore */
7675 } *aConstraint; /* Table of WHERE clause constraints */
7676 int nOrderBy; /* Number of terms in the ORDER BY clause */
7677 struct sqlite3_index_orderby {
7678 int iColumn; /* Column number */
7679 unsigned char desc; /* True for DESC. False for ASC. */
7680 } *aOrderBy; /* The ORDER BY clause */
7681 /* Outputs */
7682 struct sqlite3_index_constraint_usage {
7683 int argvIndex; /* if >0, constraint is part of argv to xFilter */
7684 unsigned char omit; /* Do not code a test for this constraint */
7685 } *aConstraintUsage;
7686 int idxNum; /* Number used to identify the index */
7687 char *idxStr; /* String, possibly obtained from sqlite3_malloc */
7688 int needToFreeIdxStr; /* Free idxStr using sqlite3_free() if true */
7689 int orderByConsumed; /* True if output is already ordered */
7690 double estimatedCost; /* Estimated cost of using this index */
7691 /* Fields below are only available in SQLite 3.8.2 and later */
7692 sqlite3_int64 estimatedRows; /* Estimated number of rows returned */
7693 /* Fields below are only available in SQLite 3.9.0 and later */
7694 int idxFlags; /* Mask of SQLITE_INDEX_SCAN_* flags */
7695 /* Fields below are only available in SQLite 3.10.0 and later */
7696 sqlite3_uint64 colUsed; /* Input: Mask of columns used by statement */
7697};
7698
7699/*
7700** CAPI3REF: Virtual Table Scan Flags
7701**
7702** Virtual table implementations are allowed to set the
7703** [sqlite3_index_info].idxFlags field to some combination of
7704** these bits.
7705*/
7706#define SQLITE_INDEX_SCAN_UNIQUE 0x00000001 /* Scan visits at most 1 row */
7707#define SQLITE_INDEX_SCAN_HEX 0x00000002 /* Display idxNum as hex */
7708 /* in EXPLAIN QUERY PLAN */
7709
7710/*
7711** CAPI3REF: Virtual Table Constraint Operator Codes
7712**
7713** These macros define the allowed values for the
7714** [sqlite3_index_info].aConstraint[].op field. Each value represents
7715** an operator that is part of a constraint term in the WHERE clause of
7716** a query that uses a [virtual table].
7717**
7718** ^The left-hand operand of the operator is given by the corresponding
7719** aConstraint[].iColumn field. ^An iColumn of -1 indicates the left-hand
7720** operand is the rowid.
7721** The SQLITE_INDEX_CONSTRAINT_LIMIT and SQLITE_INDEX_CONSTRAINT_OFFSET
7722** operators have no left-hand operand, and so for those operators the
7723** corresponding aConstraint[].iColumn is meaningless and should not be
7724** used.
7725**
7726** All operator values from SQLITE_INDEX_CONSTRAINT_FUNCTION through
7727** value 255 are reserved to represent functions that are overloaded
7728** by the [xFindFunction|xFindFunction method] of the virtual table
7729** implementation.
7730**
7731** The right-hand operands for each constraint might be accessible using
7732** the [sqlite3_vtab_rhs_value()] interface. Usually the right-hand
7733** operand is only available if it appears as a single constant literal
7734** in the input SQL. If the right-hand operand is another column or an
7735** expression (even a constant expression) or a parameter, then the
7736** sqlite3_vtab_rhs_value() probably will not be able to extract it.
7737** ^The SQLITE_INDEX_CONSTRAINT_ISNULL and
7738** SQLITE_INDEX_CONSTRAINT_ISNOTNULL operators have no right-hand operand
7739** and hence calls to sqlite3_vtab_rhs_value() for those operators will
7740** always return SQLITE_NOTFOUND.
7741**
7742** The collating sequence to be used for comparison can be found using
7743** the [sqlite3_vtab_collation()] interface. For most real-world virtual
7744** tables, the collating sequence of constraints does not matter (for example
7745** because the constraints are numeric) and so the sqlite3_vtab_collation()
7746** interface is not commonly needed.
7747*/
7748#define SQLITE_INDEX_CONSTRAINT_EQ 2
7749#define SQLITE_INDEX_CONSTRAINT_GT 4
7750#define SQLITE_INDEX_CONSTRAINT_LE 8
7751#define SQLITE_INDEX_CONSTRAINT_LT 16
7752#define SQLITE_INDEX_CONSTRAINT_GE 32
7753#define SQLITE_INDEX_CONSTRAINT_MATCH 64
7754#define SQLITE_INDEX_CONSTRAINT_LIKE 65
7755#define SQLITE_INDEX_CONSTRAINT_GLOB 66
7756#define SQLITE_INDEX_CONSTRAINT_REGEXP 67
7757#define SQLITE_INDEX_CONSTRAINT_NE 68
7758#define SQLITE_INDEX_CONSTRAINT_ISNOT 69
7759#define SQLITE_INDEX_CONSTRAINT_ISNOTNULL 70
7760#define SQLITE_INDEX_CONSTRAINT_ISNULL 71
7761#define SQLITE_INDEX_CONSTRAINT_IS 72
7762#define SQLITE_INDEX_CONSTRAINT_LIMIT 73
7763#define SQLITE_INDEX_CONSTRAINT_OFFSET 74
7764#define SQLITE_INDEX_CONSTRAINT_FUNCTION 150
7765
7766/*
7767** CAPI3REF: Register A Virtual Table Implementation
7768** METHOD: sqlite3
7769**
7770** ^These routines are used to register a new [virtual table module] name.
7771** ^Module names must be registered before
7772** creating a new [virtual table] using the module and before using a
7773** preexisting [virtual table] for the module.
7774**
7775** ^The module name is registered on the [database connection] specified
7776** by the first parameter. ^The name of the module is given by the
7777** second parameter. ^The third parameter is a pointer to
7778** the implementation of the [virtual table module]. ^The fourth
7779** parameter is an arbitrary client data pointer that is passed through
7780** into the [xCreate] and [xConnect] methods of the virtual table module
7781** when a new virtual table is being created or reinitialized.
7782**
7783** ^The sqlite3_create_module_v2() interface has a fifth parameter which
7784** is a pointer to a destructor for the pClientData. ^SQLite will
7785** invoke the destructor function (if it is not NULL) when SQLite
7786** no longer needs the pClientData pointer. ^The destructor will also
7787** be invoked if the call to sqlite3_create_module_v2() fails.
7788** ^The sqlite3_create_module()
7789** interface is equivalent to sqlite3_create_module_v2() with a NULL
7790** destructor.
7791**
7792** ^If the third parameter (the pointer to the sqlite3_module object) is
7793** NULL then no new module is created and any existing modules with the
7794** same name are dropped.
7795**
7796** See also: [sqlite3_drop_modules()]
7797*/
7798SQLITE_API int sqlite3_create_module(
7799 sqlite3 *db, /* SQLite connection to register module with */
7800 const char *zName, /* Name of the module */
7801 const sqlite3_module *p, /* Methods for the module */
7802 void *pClientData /* Client data for xCreate/xConnect */
7803);
7804SQLITE_API int sqlite3_create_module_v2(
7805 sqlite3 *db, /* SQLite connection to register module with */
7806 const char *zName, /* Name of the module */
7807 const sqlite3_module *p, /* Methods for the module */
7808 void *pClientData, /* Client data for xCreate/xConnect */
7809 void(*xDestroy)(void*) /* Module destructor function */
7810);
7811
7812/*
7813** CAPI3REF: Remove Unnecessary Virtual Table Implementations
7814** METHOD: sqlite3
7815**
7816** ^The sqlite3_drop_modules(D,L) interface removes all virtual
7817** table modules from database connection D except those named on list L.
7818** The L parameter must be either NULL or a pointer to an array of pointers
7819** to strings where the array is terminated by a single NULL pointer.
7820** ^If the L parameter is NULL, then all virtual table modules are removed.
7821**
7822** See also: [sqlite3_create_module()]
7823*/
7824SQLITE_API int sqlite3_drop_modules(
7825 sqlite3 *db, /* Remove modules from this connection */
7826 const char **azKeep /* Except, do not remove the ones named here */
7827);
7828
7829/*
7830** CAPI3REF: Virtual Table Instance Object
7831** KEYWORDS: sqlite3_vtab
7832**
7833** Every [virtual table module] implementation uses a subclass
7834** of this object to describe a particular instance
7835** of the [virtual table]. Each subclass will
7836** be tailored to the specific needs of the module implementation.
7837** The purpose of this superclass is to define certain fields that are
7838** common to all module implementations.
7839**
7840** ^Virtual tables methods can set an error message by assigning a
7841** string obtained from [sqlite3_mprintf()] to zErrMsg. The method should
7842** take care that any prior string is freed by a call to [sqlite3_free()]
7843** prior to assigning a new string to zErrMsg. ^After the error message
7844** is delivered up to the client application, the string will be automatically
7845** freed by sqlite3_free() and the zErrMsg field will be zeroed.
7846*/
7847struct sqlite3_vtab {
7848 const sqlite3_module *pModule; /* The module for this virtual table */
7849 int nRef; /* Number of open cursors */
7850 char *zErrMsg; /* Error message from sqlite3_mprintf() */
7851 /* Virtual table implementations will typically add additional fields */
7852};
7853
7854/*
7855** CAPI3REF: Virtual Table Cursor Object
7856** KEYWORDS: sqlite3_vtab_cursor {virtual table cursor}
7857**
7858** Every [virtual table module] implementation uses a subclass of the
7859** following structure to describe cursors that point into the
7860** [virtual table] and are used
7861** to loop through the virtual table. Cursors are created using the
7862** [sqlite3_module.xOpen | xOpen] method of the module and are destroyed
7863** by the [sqlite3_module.xClose | xClose] method. Cursors are used
7864** by the [xFilter], [xNext], [xEof], [xColumn], and [xRowid] methods
7865** of the module. Each module implementation will define
7866** the content of a cursor structure to suit its own needs.
7867**
7868** This superclass exists in order to define fields of the cursor that
7869** are common to all implementations.
7870*/
7871struct sqlite3_vtab_cursor {
7872 sqlite3_vtab *pVtab; /* Virtual table of this cursor */
7873 /* Virtual table implementations will typically add additional fields */
7874};
7875
7876/*
7877** CAPI3REF: Declare The Schema Of A Virtual Table
7878**
7879** ^The [xCreate] and [xConnect] methods of a
7880** [virtual table module] call this interface
7881** to declare the format (the names and datatypes of the columns) of
7882** the virtual tables they implement.
7883*/
7884SQLITE_API int sqlite3_declare_vtab(sqlite3*, const char *zSQL);
7885
7886/*
7887** CAPI3REF: Overload A Function For A Virtual Table
7888** METHOD: sqlite3
7889**
7890** ^(Virtual tables can provide alternative implementations of functions
7891** using the [xFindFunction] method of the [virtual table module].
7892** But global versions of those functions
7893** must exist in order to be overloaded.)^
7894**
7895** ^(This API makes sure a global version of a function with a particular
7896** name and number of parameters exists. If no such function exists
7897** before this API is called, a new function is created.)^ ^The implementation
7898** of the new function always causes an exception to be thrown. So
7899** the new function is not good for anything by itself. Its only
7900** purpose is to be a placeholder function that can be overloaded
7901** by a [virtual table].
7902*/
7903SQLITE_API int sqlite3_overload_function(sqlite3*, const char *zFuncName, int nArg);
7904
7905/*
7906** CAPI3REF: A Handle To An Open BLOB
7907** KEYWORDS: {BLOB handle} {BLOB handles}
7908**
7909** An instance of this object represents an open BLOB on which
7910** [sqlite3_blob_open | incremental BLOB I/O] can be performed.
7911** ^Objects of this type are created by [sqlite3_blob_open()]
7912** and destroyed by [sqlite3_blob_close()].
7913** ^The [sqlite3_blob_read()] and [sqlite3_blob_write()] interfaces
7914** can be used to read or write small subsections of the BLOB.
7915** ^The [sqlite3_blob_bytes()] interface returns the size of the BLOB in bytes.
7916*/
7917typedef struct sqlite3_blob sqlite3_blob;
7918
7919/*
7920** CAPI3REF: Open A BLOB For Incremental I/O
7921** METHOD: sqlite3
7922** CONSTRUCTOR: sqlite3_blob
7923**
7924** ^(This interfaces opens a [BLOB handle | handle] to the BLOB located
7925** in row iRow, column zColumn, table zTable in database zDb;
7926** in other words, the same BLOB that would be selected by:
7927**
7928** <pre>
7929** SELECT zColumn FROM zDb.zTable WHERE [rowid] = iRow;
7930** </pre>)^
7931**
7932** ^(Parameter zDb is not the filename that contains the database, but
7933** rather the symbolic name of the database. For attached databases, this is
7934** the name that appears after the AS keyword in the [ATTACH] statement.
7935** For the main database file, the database name is "main". For TEMP
7936** tables, the database name is "temp".)^
7937**
7938** ^If the flags parameter is non-zero, then the BLOB is opened for read
7939** and write access. ^If the flags parameter is zero, the BLOB is opened for
7940** read-only access.
7941**
7942** ^(On success, [SQLITE_OK] is returned and the new [BLOB handle] is stored
7943** in *ppBlob. Otherwise an [error code] is returned and, unless the error
7944** code is SQLITE_MISUSE, *ppBlob is set to NULL.)^ ^This means that, provided
7945** the API is not misused, it is always safe to call [sqlite3_blob_close()]
7946** on *ppBlob after this function returns.
7947**
7948** This function fails with SQLITE_ERROR if any of the following are true:
7949** <ul>
7950** <li> ^(Database zDb does not exist)^,
7951** <li> ^(Table zTable does not exist within database zDb)^,
7952** <li> ^(Table zTable is a WITHOUT ROWID table)^,
7953** <li> ^(Column zColumn does not exist)^,
7954** <li> ^(Row iRow is not present in the table)^,
7955** <li> ^(The specified column of row iRow contains a value that is not
7956** a TEXT or BLOB value)^,
7957** <li> ^(Column zColumn is part of an index, PRIMARY KEY or UNIQUE
7958** constraint and the blob is being opened for read/write access)^,
7959** <li> ^([foreign key constraints | Foreign key constraints] are enabled,
7960** column zColumn is part of a [child key] definition and the blob is
7961** being opened for read/write access)^.
7962** </ul>
7963**
7964** ^Unless it returns SQLITE_MISUSE, this function sets the
7965** [database connection] error code and message accessible via
7966** [sqlite3_errcode()] and [sqlite3_errmsg()] and related functions.
7967**
7968** A BLOB referenced by sqlite3_blob_open() may be read using the
7969** [sqlite3_blob_read()] interface and modified by using
7970** [sqlite3_blob_write()]. The [BLOB handle] can be moved to a
7971** different row of the same table using the [sqlite3_blob_reopen()]
7972** interface. However, the column, table, or database of a [BLOB handle]
7973** cannot be changed after the [BLOB handle] is opened.
7974**
7975** ^(If the row that a BLOB handle points to is modified by an
7976** [UPDATE], [DELETE], or by [ON CONFLICT] side-effects
7977** then the BLOB handle is marked as "expired".
7978** This is true if any column of the row is changed, even a column
7979** other than the one the BLOB handle is open on.)^
7980** ^Calls to [sqlite3_blob_read()] and [sqlite3_blob_write()] for
7981** an expired BLOB handle fail with a return code of [SQLITE_ABORT].
7982** ^(Changes written into a BLOB prior to the BLOB expiring are not
7983** rolled back by the expiration of the BLOB. Such changes will eventually
7984** commit if the transaction continues to completion.)^
7985**
7986** ^Use the [sqlite3_blob_bytes()] interface to determine the size of
7987** the opened blob. ^The size of a blob may not be changed by this
7988** interface. Use the [UPDATE] SQL command to change the size of a
7989** blob.
7990**
7991** ^The [sqlite3_bind_zeroblob()] and [sqlite3_result_zeroblob()] interfaces
7992** and the built-in [zeroblob] SQL function may be used to create a
7993** zero-filled blob to read or write using the incremental-blob interface.
7994**
7995** To avoid a resource leak, every open [BLOB handle] should eventually
7996** be released by a call to [sqlite3_blob_close()].
7997**
7998** See also: [sqlite3_blob_close()],
7999** [sqlite3_blob_reopen()], [sqlite3_blob_read()],
8000** [sqlite3_blob_bytes()], [sqlite3_blob_write()].
8001*/
8002SQLITE_API int sqlite3_blob_open(
8003 sqlite3*,
8004 const char *zDb,
8005 const char *zTable,
8006 const char *zColumn,
8007 sqlite3_int64 iRow,
8008 int flags,
8009 sqlite3_blob **ppBlob
8010);
8011
8012/*
8013** CAPI3REF: Move a BLOB Handle to a New Row
8014** METHOD: sqlite3_blob
8015**
8016** ^This function is used to move an existing [BLOB handle] so that it points
8017** to a different row of the same database table. ^The new row is identified
8018** by the rowid value passed as the second argument. Only the row can be
8019** changed. ^The database, table and column on which the blob handle is open
8020** remain the same. Moving an existing [BLOB handle] to a new row is
8021** faster than closing the existing handle and opening a new one.
8022**
8023** ^(The new row must meet the same criteria as for [sqlite3_blob_open()] -
8024** it must exist and there must be either a blob or text value stored in
8025** the nominated column.)^ ^If the new row is not present in the table, or if
8026** it does not contain a blob or text value, or if another error occurs, an
8027** SQLite error code is returned and the blob handle is considered aborted.
8028** ^All subsequent calls to [sqlite3_blob_read()], [sqlite3_blob_write()] or
8029** [sqlite3_blob_reopen()] on an aborted blob handle immediately return
8030** SQLITE_ABORT. ^Calling [sqlite3_blob_bytes()] on an aborted blob handle
8031** always returns zero.
8032**
8033** ^This function sets the database handle error code and message.
8034*/
8035SQLITE_API int sqlite3_blob_reopen(sqlite3_blob *, sqlite3_int64);
8036
8037/*
8038** CAPI3REF: Close A BLOB Handle
8039** DESTRUCTOR: sqlite3_blob
8040**
8041** ^This function closes an open [BLOB handle]. ^(The BLOB handle is closed
8042** unconditionally. Even if this routine returns an error code, the
8043** handle is still closed.)^
8044**
8045** ^If the blob handle being closed was opened for read-write access, and if
8046** the database is in auto-commit mode and there are no other open read-write
8047** blob handles or active write statements, the current transaction is
8048** committed. ^If an error occurs while committing the transaction, an error
8049** code is returned and the transaction rolled back.
8050**
8051** Calling this function with an argument that is not a NULL pointer or an
8052** open blob handle results in undefined behavior. ^Calling this routine
8053** with a null pointer (such as would be returned by a failed call to
8054** [sqlite3_blob_open()]) is a harmless no-op. ^Otherwise, if this function
8055** is passed a valid open blob handle, the values returned by the
8056** sqlite3_errcode() and sqlite3_errmsg() functions are set before returning.
8057*/
8058SQLITE_API int sqlite3_blob_close(sqlite3_blob *);
8059
8060/*
8061** CAPI3REF: Return The Size Of An Open BLOB
8062** METHOD: sqlite3_blob
8063**
8064** ^Returns the size in bytes of the BLOB accessible via the
8065** successfully opened [BLOB handle] in its only argument. ^The
8066** incremental blob I/O routines can only read or overwrite existing
8067** blob content; they cannot change the size of a blob.
8068**
8069** This routine only works on a [BLOB handle] which has been created
8070** by a prior successful call to [sqlite3_blob_open()] and which has not
8071** been closed by [sqlite3_blob_close()]. Passing any other pointer in
8072** to this routine results in undefined and probably undesirable behavior.
8073*/
8074SQLITE_API int sqlite3_blob_bytes(sqlite3_blob *);
8075
8076/*
8077** CAPI3REF: Read Data From A BLOB Incrementally
8078** METHOD: sqlite3_blob
8079**
8080** ^(This function is used to read data from an open [BLOB handle] into a
8081** caller-supplied buffer. N bytes of data are copied into buffer Z
8082** from the open BLOB, starting at offset iOffset.)^
8083**
8084** ^If offset iOffset is less than N bytes from the end of the BLOB,
8085** [SQLITE_ERROR] is returned and no data is read. ^If N or iOffset is
8086** less than zero, [SQLITE_ERROR] is returned and no data is read.
8087** ^The size of the blob (and hence the maximum value of N+iOffset)
8088** can be determined using the [sqlite3_blob_bytes()] interface.
8089**
8090** ^An attempt to read from an expired [BLOB handle] fails with an
8091** error code of [SQLITE_ABORT].
8092**
8093** ^(On success, sqlite3_blob_read() returns SQLITE_OK.
8094** Otherwise, an [error code] or an [extended error code] is returned.)^
8095**
8096** This routine only works on a [BLOB handle] which has been created
8097** by a prior successful call to [sqlite3_blob_open()] and which has not
8098** been closed by [sqlite3_blob_close()]. Passing any other pointer in
8099** to this routine results in undefined and probably undesirable behavior.
8100**
8101** See also: [sqlite3_blob_write()].
8102*/
8103SQLITE_API int sqlite3_blob_read(sqlite3_blob *, void *Z, int N, int iOffset);
8104
8105/*
8106** CAPI3REF: Write Data Into A BLOB Incrementally
8107** METHOD: sqlite3_blob
8108**
8109** ^(This function is used to write data into an open [BLOB handle] from a
8110** caller-supplied buffer. N bytes of data are copied from the buffer Z
8111** into the open BLOB, starting at offset iOffset.)^
8112**
8113** ^(On success, sqlite3_blob_write() returns SQLITE_OK.
8114** Otherwise, an [error code] or an [extended error code] is returned.)^
8115** ^Unless SQLITE_MISUSE is returned, this function sets the
8116** [database connection] error code and message accessible via
8117** [sqlite3_errcode()] and [sqlite3_errmsg()] and related functions.
8118**
8119** ^If the [BLOB handle] passed as the first argument was not opened for
8120** writing (the flags parameter to [sqlite3_blob_open()] was zero),
8121** this function returns [SQLITE_READONLY].
8122**
8123** This function may only modify the contents of the BLOB; it is
8124** not possible to increase the size of a BLOB using this API.
8125** ^If offset iOffset is less than N bytes from the end of the BLOB,
8126** [SQLITE_ERROR] is returned and no data is written. The size of the
8127** BLOB (and hence the maximum value of N+iOffset) can be determined
8128** using the [sqlite3_blob_bytes()] interface. ^If N or iOffset are less
8129** than zero [SQLITE_ERROR] is returned and no data is written.
8130**
8131** ^An attempt to write to an expired [BLOB handle] fails with an
8132** error code of [SQLITE_ABORT]. ^Writes to the BLOB that occurred
8133** before the [BLOB handle] expired are not rolled back by the
8134** expiration of the handle, though of course those changes might
8135** have been overwritten by the statement that expired the BLOB handle
8136** or by other independent statements.
8137**
8138** This routine only works on a [BLOB handle] which has been created
8139** by a prior successful call to [sqlite3_blob_open()] and which has not
8140** been closed by [sqlite3_blob_close()]. Passing any other pointer in
8141** to this routine results in undefined and probably undesirable behavior.
8142**
8143** See also: [sqlite3_blob_read()].
8144*/
8145SQLITE_API int sqlite3_blob_write(sqlite3_blob *, const void *z, int n, int iOffset);
8146
8147/*
8148** CAPI3REF: Virtual File System Objects
8149**
8150** A virtual filesystem (VFS) is an [sqlite3_vfs] object
8151** that SQLite uses to interact
8152** with the underlying operating system. Most SQLite builds come with a
8153** single default VFS that is appropriate for the host computer.
8154** New VFSes can be registered and existing VFSes can be unregistered.
8155** The following interfaces are provided.
8156**
8157** ^The sqlite3_vfs_find() interface returns a pointer to a VFS given its name.
8158** ^Names are case sensitive.
8159** ^Names are zero-terminated UTF-8 strings.
8160** ^If there is no match, a NULL pointer is returned.
8161** ^If zVfsName is NULL then the default VFS is returned.
8162**
8163** ^New VFSes are registered with sqlite3_vfs_register().
8164** ^Each new VFS becomes the default VFS if the makeDflt flag is set.
8165** ^The same VFS can be registered multiple times without injury.
8166** ^To make an existing VFS into the default VFS, register it again
8167** with the makeDflt flag set. If two different VFSes with the
8168** same name are registered, the behavior is undefined. If a
8169** VFS is registered with a name that is NULL or an empty string,
8170** then the behavior is undefined.
8171**
8172** ^Unregister a VFS with the sqlite3_vfs_unregister() interface.
8173** ^(If the default VFS is unregistered, another VFS is chosen as
8174** the default. The choice for the new VFS is arbitrary.)^
8175*/
8176SQLITE_API sqlite3_vfs *sqlite3_vfs_find(const char *zVfsName);
8177SQLITE_API int sqlite3_vfs_register(sqlite3_vfs*, int makeDflt);
8178SQLITE_API int sqlite3_vfs_unregister(sqlite3_vfs*);
8179
8180/*
8181** CAPI3REF: Mutexes
8182**
8183** The SQLite core uses these routines for thread
8184** synchronization. Though they are intended for internal
8185** use by SQLite, code that links against SQLite is
8186** permitted to use any of these routines.
8187**
8188** The SQLite source code contains multiple implementations
8189** of these mutex routines. An appropriate implementation
8190** is selected automatically at compile-time. The following
8191** implementations are available in the SQLite core:
8192**
8193** <ul>
8194** <li> SQLITE_MUTEX_PTHREADS
8195** <li> SQLITE_MUTEX_W32
8196** <li> SQLITE_MUTEX_NOOP
8197** </ul>
8198**
8199** The SQLITE_MUTEX_NOOP implementation is a set of routines
8200** that does no real locking and is appropriate for use in
8201** a single-threaded application. The SQLITE_MUTEX_PTHREADS and
8202** SQLITE_MUTEX_W32 implementations are appropriate for use on Unix
8203** and Windows.
8204**
8205** If SQLite is compiled with the SQLITE_MUTEX_APPDEF preprocessor
8206** macro defined (with "-DSQLITE_MUTEX_APPDEF=1"), then no mutex
8207** implementation is included with the library. In this case the
8208** application must supply a custom mutex implementation using the
8209** [SQLITE_CONFIG_MUTEX] option of the sqlite3_config() function
8210** before calling sqlite3_initialize() or any other public sqlite3_
8211** function that calls sqlite3_initialize().
8212**
8213** ^The sqlite3_mutex_alloc() routine allocates a new
8214** mutex and returns a pointer to it. ^The sqlite3_mutex_alloc()
8215** routine returns NULL if it is unable to allocate the requested
8216** mutex. The argument to sqlite3_mutex_alloc() must be one of these
8217** integer constants:
8218**
8219** <ul>
8220** <li> SQLITE_MUTEX_FAST
8221** <li> SQLITE_MUTEX_RECURSIVE
8222** <li> SQLITE_MUTEX_STATIC_MAIN
8223** <li> SQLITE_MUTEX_STATIC_MEM
8224** <li> SQLITE_MUTEX_STATIC_OPEN
8225** <li> SQLITE_MUTEX_STATIC_PRNG
8226** <li> SQLITE_MUTEX_STATIC_LRU
8227** <li> SQLITE_MUTEX_STATIC_PMEM
8228** <li> SQLITE_MUTEX_STATIC_APP1
8229** <li> SQLITE_MUTEX_STATIC_APP2
8230** <li> SQLITE_MUTEX_STATIC_APP3
8231** <li> SQLITE_MUTEX_STATIC_VFS1
8232** <li> SQLITE_MUTEX_STATIC_VFS2
8233** <li> SQLITE_MUTEX_STATIC_VFS3
8234** </ul>
8235**
8236** ^The first two constants (SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE)
8237** cause sqlite3_mutex_alloc() to create
8238** a new mutex. ^The new mutex is recursive when SQLITE_MUTEX_RECURSIVE
8239** is used but not necessarily so when SQLITE_MUTEX_FAST is used.
8240** The mutex implementation does not need to make a distinction
8241** between SQLITE_MUTEX_RECURSIVE and SQLITE_MUTEX_FAST if it does
8242** not want to. SQLite will only request a recursive mutex in
8243** cases where it really needs one. If a faster non-recursive mutex
8244** implementation is available on the host platform, the mutex subsystem
8245** might return such a mutex in response to SQLITE_MUTEX_FAST.
8246**
8247** ^The other allowed parameters to sqlite3_mutex_alloc() (anything other
8248** than SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE) each return
8249** a pointer to a static preexisting mutex. ^Nine static mutexes are
8250** used by the current version of SQLite. Future versions of SQLite
8251** may add additional static mutexes. Static mutexes are for internal
8252** use by SQLite only. Applications that use SQLite mutexes should
8253** use only the dynamic mutexes returned by SQLITE_MUTEX_FAST or
8254** SQLITE_MUTEX_RECURSIVE.
8255**
8256** ^Note that if one of the dynamic mutex parameters (SQLITE_MUTEX_FAST
8257** or SQLITE_MUTEX_RECURSIVE) is used then sqlite3_mutex_alloc()
8258** returns a different mutex on every call. ^For the static
8259** mutex types, the same mutex is returned on every call that has
8260** the same type number.
8261**
8262** ^The sqlite3_mutex_free() routine deallocates a previously
8263** allocated dynamic mutex. Attempting to deallocate a static
8264** mutex results in undefined behavior.
8265**
8266** ^The sqlite3_mutex_enter() and sqlite3_mutex_try() routines attempt
8267** to enter a mutex. ^If another thread is already within the mutex,
8268** sqlite3_mutex_enter() will block and sqlite3_mutex_try() will return
8269** SQLITE_BUSY. ^The sqlite3_mutex_try() interface returns [SQLITE_OK]
8270** upon successful entry. ^(Mutexes created using
8271** SQLITE_MUTEX_RECURSIVE can be entered multiple times by the same thread.
8272** In such cases, the
8273** mutex must be exited an equal number of times before another thread
8274** can enter.)^ If the same thread tries to enter any mutex other
8275** than an SQLITE_MUTEX_RECURSIVE more than once, the behavior is undefined.
8276**
8277** ^(Some systems (for example, Windows 95) do not support the operation
8278** implemented by sqlite3_mutex_try(). On those systems, sqlite3_mutex_try()
8279** will always return SQLITE_BUSY. In most cases the SQLite core only uses
8280** sqlite3_mutex_try() as an optimization, so this is acceptable
8281** behavior. The exceptions are unix builds that set the
8282** SQLITE_ENABLE_SETLK_TIMEOUT build option. In that case a working
8283** sqlite3_mutex_try() is required.)^
8284**
8285** ^The sqlite3_mutex_leave() routine exits a mutex that was
8286** previously entered by the same thread. The behavior
8287** is undefined if the mutex is not currently entered by the
8288** calling thread or is not currently allocated.
8289**
8290** ^If the argument to sqlite3_mutex_enter(), sqlite3_mutex_try(),
8291** sqlite3_mutex_leave(), or sqlite3_mutex_free() is a NULL pointer,
8292** then any of the four routines behaves as a no-op.
8293**
8294** See also: [sqlite3_mutex_held()] and [sqlite3_mutex_notheld()].
8295*/
8296SQLITE_API sqlite3_mutex *sqlite3_mutex_alloc(int);
8297SQLITE_API void sqlite3_mutex_free(sqlite3_mutex*);
8298SQLITE_API void sqlite3_mutex_enter(sqlite3_mutex*);
8299SQLITE_API int sqlite3_mutex_try(sqlite3_mutex*);
8300SQLITE_API void sqlite3_mutex_leave(sqlite3_mutex*);
8301
8302/*
8303** CAPI3REF: Mutex Methods Object
8304**
8305** An instance of this structure defines the low-level routines
8306** used to allocate and use mutexes.
8307**
8308** Usually, the default mutex implementations provided by SQLite are
8309** sufficient, however the application has the option of substituting a custom
8310** implementation for specialized deployments or systems for which SQLite
8311** does not provide a suitable implementation. In this case, the application
8312** creates and populates an instance of this structure to pass
8313** to sqlite3_config() along with the [SQLITE_CONFIG_MUTEX] option.
8314** Additionally, an instance of this structure can be used as an
8315** output variable when querying the system for the current mutex
8316** implementation, using the [SQLITE_CONFIG_GETMUTEX] option.
8317**
8318** ^The xMutexInit method defined by this structure is invoked as
8319** part of system initialization by the sqlite3_initialize() function.
8320** ^The xMutexInit routine is called by SQLite exactly once for each
8321** effective call to [sqlite3_initialize()].
8322**
8323** ^The xMutexEnd method defined by this structure is invoked as
8324** part of system shutdown by the sqlite3_shutdown() function. The
8325** implementation of this method is expected to release all outstanding
8326** resources obtained by the mutex methods implementation, especially
8327** those obtained by the xMutexInit method. ^The xMutexEnd()
8328** interface is invoked exactly once for each call to [sqlite3_shutdown()].
8329**
8330** ^(The remaining seven methods defined by this structure (xMutexAlloc,
8331** xMutexFree, xMutexEnter, xMutexTry, xMutexLeave, xMutexHeld and
8332** xMutexNotheld) implement the following interfaces (respectively):
8333**
8334** <ul>
8335** <li> [sqlite3_mutex_alloc()] </li>
8336** <li> [sqlite3_mutex_free()] </li>
8337** <li> [sqlite3_mutex_enter()] </li>
8338** <li> [sqlite3_mutex_try()] </li>
8339** <li> [sqlite3_mutex_leave()] </li>
8340** <li> [sqlite3_mutex_held()] </li>
8341** <li> [sqlite3_mutex_notheld()] </li>
8342** </ul>)^
8343**
8344** The only difference is that the public sqlite3_XXX functions enumerated
8345** above silently ignore any invocations that pass a NULL pointer instead
8346** of a valid mutex handle. The implementations of the methods defined
8347** by this structure are not required to handle this case. The results
8348** of passing a NULL pointer instead of a valid mutex handle are undefined
8349** (i.e. it is acceptable to provide an implementation that segfaults if
8350** it is passed a NULL pointer).
8351**
8352** The xMutexInit() method must be threadsafe. It must be harmless to
8353** invoke xMutexInit() multiple times within the same process and without
8354** intervening calls to xMutexEnd(). Second and subsequent calls to
8355** xMutexInit() must be no-ops.
8356**
8357** xMutexInit() must not use SQLite memory allocation ([sqlite3_malloc()]
8358** and its associates). Similarly, xMutexAlloc() must not use SQLite memory
8359** allocation for a static mutex. ^However xMutexAlloc() may use SQLite
8360** memory allocation for a fast or recursive mutex.
8361**
8362** ^SQLite will invoke the xMutexEnd() method when [sqlite3_shutdown()] is
8363** called, but only if the prior call to xMutexInit returned SQLITE_OK.
8364** If xMutexInit fails in any way, it is expected to clean up after itself
8365** prior to returning.
8366*/
8367typedef struct sqlite3_mutex_methods sqlite3_mutex_methods;
8368struct sqlite3_mutex_methods {
8369 int (*xMutexInit)(void);
8370 int (*xMutexEnd)(void);
8371 sqlite3_mutex *(*xMutexAlloc)(int);
8372 void (*xMutexFree)(sqlite3_mutex *);
8373 void (*xMutexEnter)(sqlite3_mutex *);
8374 int (*xMutexTry)(sqlite3_mutex *);
8375 void (*xMutexLeave)(sqlite3_mutex *);
8376 int (*xMutexHeld)(sqlite3_mutex *);
8377 int (*xMutexNotheld)(sqlite3_mutex *);
8378};
8379
8380/*
8381** CAPI3REF: Mutex Verification Routines
8382**
8383** The sqlite3_mutex_held() and sqlite3_mutex_notheld() routines
8384** are intended for use inside assert() statements. The SQLite core
8385** never uses these routines except inside an assert() and applications
8386** are advised to follow the lead of the core. The SQLite core only
8387** provides implementations for these routines when it is compiled
8388** with the SQLITE_DEBUG flag. External mutex implementations
8389** are only required to provide these routines if SQLITE_DEBUG is
8390** defined and if NDEBUG is not defined.
8391**
8392** These routines should return true if the mutex in their argument
8393** is held or not held, respectively, by the calling thread.
8394**
8395** The implementation is not required to provide versions of these
8396** routines that actually work. If the implementation does not provide working
8397** versions of these routines, it should at least provide stubs that always
8398** return true so that one does not get spurious assertion failures.
8399**
8400** If the argument to sqlite3_mutex_held() is a NULL pointer then
8401** the routine should return 1. This seems counter-intuitive since
8402** clearly the mutex cannot be held if it does not exist. But
8403** the reason the mutex does not exist is because the build is not
8404** using mutexes. And we do not want the assert() containing the
8405** call to sqlite3_mutex_held() to fail, so a non-zero return is
8406** the appropriate thing to do. The sqlite3_mutex_notheld()
8407** interface should also return 1 when given a NULL pointer.
8408*/
8409#ifndef NDEBUG
8410SQLITE_API int sqlite3_mutex_held(sqlite3_mutex*);
8411SQLITE_API int sqlite3_mutex_notheld(sqlite3_mutex*);
8412#endif
8413
8414/*
8415** CAPI3REF: Mutex Types
8416**
8417** The [sqlite3_mutex_alloc()] interface takes a single argument
8418** which is one of these integer constants.
8419**
8420** The set of static mutexes may change from one SQLite release to the
8421** next. Applications that override the built-in mutex logic must be
8422** prepared to accommodate additional static mutexes.
8423*/
8424#define SQLITE_MUTEX_FAST 0
8425#define SQLITE_MUTEX_RECURSIVE 1
8426#define SQLITE_MUTEX_STATIC_MAIN 2
8427#define SQLITE_MUTEX_STATIC_MEM 3 /* sqlite3_malloc() */
8428#define SQLITE_MUTEX_STATIC_MEM2 4 /* NOT USED */
8429#define SQLITE_MUTEX_STATIC_OPEN 4 /* sqlite3BtreeOpen() */
8430#define SQLITE_MUTEX_STATIC_PRNG 5 /* sqlite3_randomness() */
8431#define SQLITE_MUTEX_STATIC_LRU 6 /* lru page list */
8432#define SQLITE_MUTEX_STATIC_LRU2 7 /* NOT USED */
8433#define SQLITE_MUTEX_STATIC_PMEM 7 /* sqlite3PageMalloc() */
8434#define SQLITE_MUTEX_STATIC_APP1 8 /* For use by application */
8435#define SQLITE_MUTEX_STATIC_APP2 9 /* For use by application */
8436#define SQLITE_MUTEX_STATIC_APP3 10 /* For use by application */
8437#define SQLITE_MUTEX_STATIC_VFS1 11 /* For use by built-in VFS */
8438#define SQLITE_MUTEX_STATIC_VFS2 12 /* For use by extension VFS */
8439#define SQLITE_MUTEX_STATIC_VFS3 13 /* For use by application VFS */
8440
8441/* Legacy compatibility: */
8442#define SQLITE_MUTEX_STATIC_MASTER 2
8443
8444
8445/*
8446** CAPI3REF: Retrieve the mutex for a database connection
8447** METHOD: sqlite3
8448**
8449** ^This interface returns a pointer to the [sqlite3_mutex] object that
8450** serializes access to the [database connection] given in the argument
8451** when the [threading mode] is Serialized.
8452** ^If the [threading mode] is Single-thread or Multi-thread then this
8453** routine returns a NULL pointer.
8454*/
8455SQLITE_API sqlite3_mutex *sqlite3_db_mutex(sqlite3*);
8456
8457/*
8458** CAPI3REF: Low-Level Control Of Database Files
8459** METHOD: sqlite3
8460** KEYWORDS: {file control}
8461**
8462** ^The [sqlite3_file_control()] interface makes a direct call to the
8463** xFileControl method for the [sqlite3_io_methods] object associated
8464** with a particular database identified by the second argument. ^The
8465** name of the database is "main" for the main database or "temp" for the
8466** TEMP database, or the name that appears after the AS keyword for
8467** databases that are added using the [ATTACH] SQL command.
8468** ^A NULL pointer can be used in place of "main" to refer to the
8469** main database file.
8470** ^The third and fourth parameters to this routine
8471** are passed directly through to the second and third parameters of
8472** the xFileControl method. ^The return value of the xFileControl
8473** method becomes the return value of this routine.
8474**
8475** A few opcodes for [sqlite3_file_control()] are handled directly
8476** by the SQLite core and never invoke the
8477** sqlite3_io_methods.xFileControl method.
8478** ^The [SQLITE_FCNTL_FILE_POINTER] value for the op parameter causes
8479** a pointer to the underlying [sqlite3_file] object to be written into
8480** the space pointed to by the 4th parameter. The
8481** [SQLITE_FCNTL_JOURNAL_POINTER] works similarly except that it returns
8482** the [sqlite3_file] object associated with the journal file instead of
8483** the main database. The [SQLITE_FCNTL_VFS_POINTER] opcode returns
8484** a pointer to the underlying [sqlite3_vfs] object for the file.
8485** The [SQLITE_FCNTL_DATA_VERSION] returns the data version counter
8486** from the pager.
8487**
8488** ^If the second parameter (zDbName) does not match the name of any
8489** open database file, then SQLITE_ERROR is returned. ^This error
8490** code is not remembered and will not be recalled by [sqlite3_errcode()]
8491** or [sqlite3_errmsg()]. The underlying xFileControl method might
8492** also return SQLITE_ERROR. There is no way to distinguish between
8493** an incorrect zDbName and an SQLITE_ERROR return from the underlying
8494** xFileControl method.
8495**
8496** See also: [file control opcodes]
8497*/
8498SQLITE_API int sqlite3_file_control(sqlite3*, const char *zDbName, int op, void*);
8499
8500/*
8501** CAPI3REF: Testing Interface
8502**
8503** ^The sqlite3_test_control() interface is used to read out internal
8504** state of SQLite and to inject faults into SQLite for testing
8505** purposes. ^The first parameter is an operation code that determines
8506** the number, meaning, and operation of all subsequent parameters.
8507**
8508** This interface is not for use by applications. It exists solely
8509** for verifying the correct operation of the SQLite library. Depending
8510** on how the SQLite library is compiled, this interface might not exist.
8511**
8512** The details of the operation codes, their meanings, the parameters
8513** they take, and what they do are all subject to change without notice.
8514** Unlike most of the SQLite API, this function is not guaranteed to
8515** operate consistently from one release to the next.
8516*/
8517SQLITE_API int sqlite3_test_control(int op, ...);
8518
8519/*
8520** CAPI3REF: Testing Interface Operation Codes
8521**
8522** These constants are the valid operation code parameters used
8523** as the first argument to [sqlite3_test_control()].
8524**
8525** These parameters and their meanings are subject to change
8526** without notice. These values are for testing purposes only.
8527** Applications should not use any of these parameters or the
8528** [sqlite3_test_control()] interface.
8529*/
8530#define SQLITE_TESTCTRL_FIRST 5
8531#define SQLITE_TESTCTRL_PRNG_SAVE 5
8532#define SQLITE_TESTCTRL_PRNG_RESTORE 6
8533#define SQLITE_TESTCTRL_PRNG_RESET 7 /* NOT USED */
8534#define SQLITE_TESTCTRL_FK_NO_ACTION 7
8535#define SQLITE_TESTCTRL_BITVEC_TEST 8
8536#define SQLITE_TESTCTRL_FAULT_INSTALL 9
8537#define SQLITE_TESTCTRL_BENIGN_MALLOC_HOOKS 10
8538#define SQLITE_TESTCTRL_PENDING_BYTE 11
8539#define SQLITE_TESTCTRL_ASSERT 12
8540#define SQLITE_TESTCTRL_ALWAYS 13
8541#define SQLITE_TESTCTRL_RESERVE 14 /* NOT USED */
8542#define SQLITE_TESTCTRL_JSON_SELFCHECK 14
8543#define SQLITE_TESTCTRL_OPTIMIZATIONS 15
8544#define SQLITE_TESTCTRL_ISKEYWORD 16 /* NOT USED */
8545#define SQLITE_TESTCTRL_GETOPT 16
8546#define SQLITE_TESTCTRL_SCRATCHMALLOC 17 /* NOT USED */
8547#define SQLITE_TESTCTRL_INTERNAL_FUNCTIONS 17
8548#define SQLITE_TESTCTRL_LOCALTIME_FAULT 18
8549#define SQLITE_TESTCTRL_EXPLAIN_STMT 19 /* NOT USED */
8550#define SQLITE_TESTCTRL_ONCE_RESET_THRESHOLD 19
8551#define SQLITE_TESTCTRL_NEVER_CORRUPT 20
8552#define SQLITE_TESTCTRL_VDBE_COVERAGE 21
8553#define SQLITE_TESTCTRL_BYTEORDER 22
8554#define SQLITE_TESTCTRL_ISINIT 23
8555#define SQLITE_TESTCTRL_SORTER_MMAP 24
8556#define SQLITE_TESTCTRL_IMPOSTER 25
8557#define SQLITE_TESTCTRL_PARSER_COVERAGE 26
8558#define SQLITE_TESTCTRL_RESULT_INTREAL 27
8559#define SQLITE_TESTCTRL_PRNG_SEED 28
8560#define SQLITE_TESTCTRL_EXTRA_SCHEMA_CHECKS 29
8561#define SQLITE_TESTCTRL_SEEK_COUNT 30
8562#define SQLITE_TESTCTRL_TRACEFLAGS 31
8563#define SQLITE_TESTCTRL_TUNE 32
8564#define SQLITE_TESTCTRL_LOGEST 33
8565#define SQLITE_TESTCTRL_USELONGDOUBLE 34 /* NOT USED */
8566#define SQLITE_TESTCTRL_LAST 34 /* Largest TESTCTRL */
8567
8568/*
8569** CAPI3REF: SQL Keyword Checking
8570**
8571** These routines provide access to the set of SQL language keywords
8572** recognized by SQLite. Applications can use these routines to determine
8573** whether or not a specific identifier needs to be escaped (for example,
8574** by enclosing in double-quotes) so as not to confuse the parser.
8575**
8576** The sqlite3_keyword_count() interface returns the number of distinct
8577** keywords understood by SQLite.
8578**
8579** The sqlite3_keyword_name(N,Z,L) interface finds the 0-based N-th keyword and
8580** makes *Z point to that keyword expressed as UTF8 and writes the number
8581** of bytes in the keyword into *L. The string that *Z points to is not
8582** zero-terminated. The sqlite3_keyword_name(N,Z,L) routine returns
8583** SQLITE_OK if N is within bounds and SQLITE_ERROR if not. If either Z
8584** or L are NULL or invalid pointers then calls to
8585** sqlite3_keyword_name(N,Z,L) result in undefined behavior.
8586**
8587** The sqlite3_keyword_check(Z,L) interface checks to see whether or not
8588** the L-byte UTF8 identifier that Z points to is a keyword, returning non-zero
8589** if it is and zero if not.
8590**
8591** The parser used by SQLite is forgiving. It is often possible to use
8592** a keyword as an identifier as long as such use does not result in a
8593** parsing ambiguity. For example, the statement
8594** "CREATE TABLE BEGIN(REPLACE,PRAGMA,END);" is accepted by SQLite, and
8595** creates a new table named "BEGIN" with three columns named
8596** "REPLACE", "PRAGMA", and "END". Nevertheless, best practice is to avoid
8597** using keywords as identifiers. Common techniques used to avoid keyword
8598** name collisions include:
8599** <ul>
8600** <li> Put all identifier names inside double-quotes. This is the official
8601** SQL way to escape identifier names.
8602** <li> Put identifier names inside [...]. This is not standard SQL,
8603** but it is what SQL Server does and so lots of programmers use this
8604** technique.
8605** <li> Begin every identifier with the letter "Z" as no SQL keywords start
8606** with "Z".
8607** <li> Include a digit somewhere in every identifier name.
8608** </ul>
8609**
8610** Note that the number of keywords understood by SQLite can depend on
8611** compile-time options. For example, "VACUUM" is not a keyword if
8612** SQLite is compiled with the [-DSQLITE_OMIT_VACUUM] option. Also,
8613** new keywords may be added to future releases of SQLite.
8614*/
8615SQLITE_API int sqlite3_keyword_count(void);
8616SQLITE_API int sqlite3_keyword_name(int,const char**,int*);
8617SQLITE_API int sqlite3_keyword_check(const char*,int);
8618
8619/*
8620** CAPI3REF: Dynamic String Object
8621** KEYWORDS: {dynamic string}
8622**
8623** An instance of the sqlite3_str object contains a dynamically-sized
8624** string under construction.
8625**
8626** The lifecycle of an sqlite3_str object is as follows:
8627** <ol>
8628** <li> ^The sqlite3_str object is created using [sqlite3_str_new()].
8629** <li> ^Text is appended to the sqlite3_str object using various
8630** methods, such as [sqlite3_str_appendf()].
8631** <li> ^The sqlite3_str object is destroyed and the string it created
8632** is returned using the [sqlite3_str_finish()] interface.
8633** </ol>
8634*/
8635typedef struct sqlite3_str sqlite3_str;
8636
8637/*
8638** CAPI3REF: Create A New Dynamic String Object
8639** CONSTRUCTOR: sqlite3_str
8640**
8641** ^The [sqlite3_str_new(D)] interface allocates and initializes
8642** a new [sqlite3_str] object. To avoid memory leaks, the object returned by
8643** [sqlite3_str_new()] must be freed by a subsequent call to
8644** [sqlite3_str_finish(X)].
8645**
8646** ^The [sqlite3_str_new(D)] interface always returns a pointer to a
8647** valid [sqlite3_str] object, though in the event of an out-of-memory
8648** error the returned object might be a special singleton that will
8649** silently reject new text, always return SQLITE_NOMEM from
8650** [sqlite3_str_errcode()], always return 0 for
8651** [sqlite3_str_length()], and always return NULL from
8652** [sqlite3_str_finish(X)]. It is always safe to use the value
8653** returned by [sqlite3_str_new(D)] as the sqlite3_str parameter
8654** to any of the other [sqlite3_str] methods.
8655**
8656** The D parameter to [sqlite3_str_new(D)] may be NULL. If the
8657** D parameter in [sqlite3_str_new(D)] is not NULL, then the maximum
8658** length of the string contained in the [sqlite3_str] object will be
8659** the value set for [sqlite3_limit](D,[SQLITE_LIMIT_LENGTH]) instead
8660** of [SQLITE_MAX_LENGTH].
8661*/
8662SQLITE_API sqlite3_str *sqlite3_str_new(sqlite3*);
8663
8664/*
8665** CAPI3REF: Finalize A Dynamic String
8666** DESTRUCTOR: sqlite3_str
8667**
8668** ^The [sqlite3_str_finish(X)] interface destroys the sqlite3_str object X
8669** and returns a pointer to a memory buffer obtained from [sqlite3_malloc64()]
8670** that contains the constructed string. The calling application should
8671** pass the returned value to [sqlite3_free()] to avoid a memory leak.
8672** ^The [sqlite3_str_finish(X)] interface may return a NULL pointer if any
8673** errors were encountered during construction of the string. ^The
8674** [sqlite3_str_finish(X)] interface will also return a NULL pointer if the
8675** string in [sqlite3_str] object X is zero bytes long.
8676*/
8677SQLITE_API char *sqlite3_str_finish(sqlite3_str*);
8678
8679/*
8680** CAPI3REF: Add Content To A Dynamic String
8681** METHOD: sqlite3_str
8682**
8683** These interfaces add content to an sqlite3_str object previously obtained
8684** from [sqlite3_str_new()].
8685**
8686** ^The [sqlite3_str_appendf(X,F,...)] and
8687** [sqlite3_str_vappendf(X,F,V)] interfaces uses the [built-in printf]
8688** functionality of SQLite to append formatted text onto the end of
8689** [sqlite3_str] object X.
8690**
8691** ^The [sqlite3_str_append(X,S,N)] method appends exactly N bytes from string S
8692** onto the end of the [sqlite3_str] object X. N must be non-negative.
8693** S must contain at least N non-zero bytes of content. To append a
8694** zero-terminated string in its entirety, use the [sqlite3_str_appendall()]
8695** method instead.
8696**
8697** ^The [sqlite3_str_appendall(X,S)] method appends the complete content of
8698** zero-terminated string S onto the end of [sqlite3_str] object X.
8699**
8700** ^The [sqlite3_str_appendchar(X,N,C)] method appends N copies of the
8701** single-byte character C onto the end of [sqlite3_str] object X.
8702** ^This method can be used, for example, to add whitespace indentation.
8703**
8704** ^The [sqlite3_str_reset(X)] method resets the string under construction
8705** inside [sqlite3_str] object X back to zero bytes in length.
8706**
8707** These methods do not return a result code. ^If an error occurs, that fact
8708** is recorded in the [sqlite3_str] object and can be recovered by a
8709** subsequent call to [sqlite3_str_errcode(X)].
8710*/
8711SQLITE_API void sqlite3_str_appendf(sqlite3_str*, const char *zFormat, ...);
8712SQLITE_API void sqlite3_str_vappendf(sqlite3_str*, const char *zFormat, va_list);
8713SQLITE_API void sqlite3_str_append(sqlite3_str*, const char *zIn, int N);
8714SQLITE_API void sqlite3_str_appendall(sqlite3_str*, const char *zIn);
8715SQLITE_API void sqlite3_str_appendchar(sqlite3_str*, int N, char C);
8716SQLITE_API void sqlite3_str_reset(sqlite3_str*);
8717
8718/*
8719** CAPI3REF: Status Of A Dynamic String
8720** METHOD: sqlite3_str
8721**
8722** These interfaces return the current status of an [sqlite3_str] object.
8723**
8724** ^If any prior errors have occurred while constructing the dynamic string
8725** in sqlite3_str X, then the [sqlite3_str_errcode(X)] method will return
8726** an appropriate error code. ^The [sqlite3_str_errcode(X)] method returns
8727** [SQLITE_NOMEM] following any out-of-memory error, or
8728** [SQLITE_TOOBIG] if the size of the dynamic string exceeds
8729** [SQLITE_MAX_LENGTH], or [SQLITE_OK] if there have been no errors.
8730**
8731** ^The [sqlite3_str_length(X)] method returns the current length, in bytes,
8732** of the dynamic string under construction in [sqlite3_str] object X.
8733** ^The length returned by [sqlite3_str_length(X)] does not include the
8734** zero-termination byte.
8735**
8736** ^The [sqlite3_str_value(X)] method returns a pointer to the current
8737** content of the dynamic string under construction in X. The value
8738** returned by [sqlite3_str_value(X)] is managed by the sqlite3_str object X
8739** and might be freed or altered by any subsequent method on the same
8740** [sqlite3_str] object. Applications must not use the pointer returned by
8741** [sqlite3_str_value(X)] after any subsequent method call on the same
8742** object. ^Applications may change the content of the string returned
8743** by [sqlite3_str_value(X)] as long as they do not write into any bytes
8744** outside the range of 0 to [sqlite3_str_length(X)] and do not read or
8745** write any byte after any subsequent sqlite3_str method call.
8746*/
8747SQLITE_API int sqlite3_str_errcode(sqlite3_str*);
8748SQLITE_API int sqlite3_str_length(sqlite3_str*);
8749SQLITE_API char *sqlite3_str_value(sqlite3_str*);
8750
8751/*
8752** CAPI3REF: SQLite Runtime Status
8753**
8754** ^These interfaces are used to retrieve runtime status information
8755** about the performance of SQLite, and optionally to reset various
8756** highwater marks. ^The first argument is an integer code for
8757** the specific parameter to measure. ^(Recognized integer codes
8758** are of the form [status parameters | SQLITE_STATUS_...].)^
8759** ^The current value of the parameter is returned into *pCurrent.
8760** ^The highest recorded value is returned in *pHighwater. ^If the
8761** resetFlag is true, then the highest record value is reset after
8762** *pHighwater is written. ^(Some parameters do not record the highest
8763** value. For those parameters
8764** nothing is written into *pHighwater and the resetFlag is ignored.)^
8765** ^(Other parameters record only the highwater mark and not the current
8766** value. For these latter parameters nothing is written into *pCurrent.)^
8767**
8768** ^The sqlite3_status() and sqlite3_status64() routines return
8769** SQLITE_OK on success and a non-zero [error code] on failure.
8770**
8771** If either the current value or the highwater mark is too large to
8772** be represented by a 32-bit integer, then the values returned by
8773** sqlite3_status() are undefined.
8774**
8775** See also: [sqlite3_db_status()]
8776*/
8777SQLITE_API int sqlite3_status(int op, int *pCurrent, int *pHighwater, int resetFlag);
8778SQLITE_API int sqlite3_status64(
8779 int op,
8780 sqlite3_int64 *pCurrent,
8781 sqlite3_int64 *pHighwater,
8782 int resetFlag
8783);
8784
8785
8786/*
8787** CAPI3REF: Status Parameters
8788** KEYWORDS: {status parameters}
8789**
8790** These integer constants designate various run-time status parameters
8791** that can be returned by [sqlite3_status()].
8792**
8793** <dl>
8794** [[SQLITE_STATUS_MEMORY_USED]] ^(<dt>SQLITE_STATUS_MEMORY_USED</dt>
8795** <dd>This parameter is the current amount of memory checked out
8796** using [sqlite3_malloc()], either directly or indirectly. The
8797** figure includes calls made to [sqlite3_malloc()] by the application
8798** and internal memory usage by the SQLite library. Auxiliary page-cache
8799** memory controlled by [SQLITE_CONFIG_PAGECACHE] is not included in
8800** this parameter. The amount returned is the sum of the allocation
8801** sizes as reported by the xSize method in [sqlite3_mem_methods].</dd>)^
8802**
8803** [[SQLITE_STATUS_MALLOC_SIZE]] ^(<dt>SQLITE_STATUS_MALLOC_SIZE</dt>
8804** <dd>This parameter records the largest memory allocation request
8805** handed to [sqlite3_malloc()] or [sqlite3_realloc()] (or their
8806** internal equivalents). Only the value returned in the
8807** *pHighwater parameter to [sqlite3_status()] is of interest.
8808** The value written into the *pCurrent parameter is undefined.</dd>)^
8809**
8810** [[SQLITE_STATUS_MALLOC_COUNT]] ^(<dt>SQLITE_STATUS_MALLOC_COUNT</dt>
8811** <dd>This parameter records the number of separate memory allocations
8812** currently checked out.</dd>)^
8813**
8814** [[SQLITE_STATUS_PAGECACHE_USED]] ^(<dt>SQLITE_STATUS_PAGECACHE_USED</dt>
8815** <dd>This parameter returns the number of pages used out of the
8816** [pagecache memory allocator] that was configured using
8817** [SQLITE_CONFIG_PAGECACHE]. The
8818** value returned is in pages, not in bytes.</dd>)^
8819**
8820** [[SQLITE_STATUS_PAGECACHE_OVERFLOW]]
8821** ^(<dt>SQLITE_STATUS_PAGECACHE_OVERFLOW</dt>
8822** <dd>This parameter returns the number of bytes of page cache
8823** allocation which could not be satisfied by the [SQLITE_CONFIG_PAGECACHE]
8824** buffer and where forced to overflow to [sqlite3_malloc()]. The
8825** returned value includes allocations that overflowed because they
8826** were too large (they were larger than the "sz" parameter to
8827** [SQLITE_CONFIG_PAGECACHE]) and allocations that overflowed because
8828** no space was left in the page cache.</dd>)^
8829**
8830** [[SQLITE_STATUS_PAGECACHE_SIZE]] ^(<dt>SQLITE_STATUS_PAGECACHE_SIZE</dt>
8831** <dd>This parameter records the largest memory allocation request
8832** handed to the [pagecache memory allocator]. Only the value returned in the
8833** *pHighwater parameter to [sqlite3_status()] is of interest.
8834** The value written into the *pCurrent parameter is undefined.</dd>)^
8835**
8836** [[SQLITE_STATUS_SCRATCH_USED]] <dt>SQLITE_STATUS_SCRATCH_USED</dt>
8837** <dd>No longer used.</dd>
8838**
8839** [[SQLITE_STATUS_SCRATCH_OVERFLOW]] ^(<dt>SQLITE_STATUS_SCRATCH_OVERFLOW</dt>
8840** <dd>No longer used.</dd>
8841**
8842** [[SQLITE_STATUS_SCRATCH_SIZE]] <dt>SQLITE_STATUS_SCRATCH_SIZE</dt>
8843** <dd>No longer used.</dd>
8844**
8845** [[SQLITE_STATUS_PARSER_STACK]] ^(<dt>SQLITE_STATUS_PARSER_STACK</dt>
8846** <dd>The *pHighwater parameter records the deepest parser stack.
8847** The *pCurrent value is undefined. The *pHighwater value is only
8848** meaningful if SQLite is compiled with [YYTRACKMAXSTACKDEPTH].</dd>)^
8849** </dl>
8850**
8851** New status parameters may be added from time to time.
8852*/
8853#define SQLITE_STATUS_MEMORY_USED 0
8854#define SQLITE_STATUS_PAGECACHE_USED 1
8855#define SQLITE_STATUS_PAGECACHE_OVERFLOW 2
8856#define SQLITE_STATUS_SCRATCH_USED 3 /* NOT USED */
8857#define SQLITE_STATUS_SCRATCH_OVERFLOW 4 /* NOT USED */
8858#define SQLITE_STATUS_MALLOC_SIZE 5
8859#define SQLITE_STATUS_PARSER_STACK 6
8860#define SQLITE_STATUS_PAGECACHE_SIZE 7
8861#define SQLITE_STATUS_SCRATCH_SIZE 8 /* NOT USED */
8862#define SQLITE_STATUS_MALLOC_COUNT 9
8863
8864/*
8865** CAPI3REF: Database Connection Status
8866** METHOD: sqlite3
8867**
8868** ^This interface is used to retrieve runtime status information
8869** about a single [database connection]. ^The first argument is the
8870** database connection object to be interrogated. ^The second argument
8871** is an integer constant, taken from the set of
8872** [SQLITE_DBSTATUS options], that
8873** determines the parameter to interrogate. The set of
8874** [SQLITE_DBSTATUS options] is likely
8875** to grow in future releases of SQLite.
8876**
8877** ^The current value of the requested parameter is written into *pCur
8878** and the highest instantaneous value is written into *pHiwtr. ^If
8879** the resetFlg is true, then the highest instantaneous value is
8880** reset back down to the current value.
8881**
8882** ^The sqlite3_db_status() routine returns SQLITE_OK on success and a
8883** non-zero [error code] on failure.
8884**
8885** See also: [sqlite3_status()] and [sqlite3_stmt_status()].
8886*/
8887SQLITE_API int sqlite3_db_status(sqlite3*, int op, int *pCur, int *pHiwtr, int resetFlg);
8888
8889/*
8890** CAPI3REF: Status Parameters for database connections
8891** KEYWORDS: {SQLITE_DBSTATUS options}
8892**
8893** These constants are the available integer "verbs" that can be passed as
8894** the second argument to the [sqlite3_db_status()] interface.
8895**
8896** New verbs may be added in future releases of SQLite. Existing verbs
8897** might be discontinued. Applications should check the return code from
8898** [sqlite3_db_status()] to make sure that the call worked.
8899** The [sqlite3_db_status()] interface will return a non-zero error code
8900** if a discontinued or unsupported verb is invoked.
8901**
8902** <dl>
8903** [[SQLITE_DBSTATUS_LOOKASIDE_USED]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_USED</dt>
8904** <dd>This parameter returns the number of lookaside memory slots currently
8905** checked out.</dd>)^
8906**
8907** [[SQLITE_DBSTATUS_LOOKASIDE_HIT]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_HIT</dt>
8908** <dd>This parameter returns the number of malloc attempts that were
8909** satisfied using lookaside memory. Only the high-water value is meaningful;
8910** the current value is always zero.</dd>)^
8911**
8912** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE]]
8913** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE</dt>
8914** <dd>This parameter returns the number of malloc attempts that might have
8915** been satisfied using lookaside memory but failed due to the amount of
8916** memory requested being larger than the lookaside slot size.
8917** Only the high-water value is meaningful;
8918** the current value is always zero.</dd>)^
8919**
8920** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL]]
8921** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL</dt>
8922** <dd>This parameter returns the number of malloc attempts that might have
8923** been satisfied using lookaside memory but failed due to all lookaside
8924** memory already being in use.
8925** Only the high-water value is meaningful;
8926** the current value is always zero.</dd>)^
8927**
8928** [[SQLITE_DBSTATUS_CACHE_USED]] ^(<dt>SQLITE_DBSTATUS_CACHE_USED</dt>
8929** <dd>This parameter returns the approximate number of bytes of heap
8930** memory used by all pager caches associated with the database connection.)^
8931** ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_USED is always 0.
8932** </dd>
8933**
8934** [[SQLITE_DBSTATUS_CACHE_USED_SHARED]]
8935** ^(<dt>SQLITE_DBSTATUS_CACHE_USED_SHARED</dt>
8936** <dd>This parameter is similar to DBSTATUS_CACHE_USED, except that if a
8937** pager cache is shared between two or more connections the bytes of heap
8938** memory used by that pager cache is divided evenly between the attached
8939** connections.)^ In other words, if none of the pager caches associated
8940** with the database connection are shared, this request returns the same
8941** value as DBSTATUS_CACHE_USED. Or, if one or more of the pager caches are
8942** shared, the value returned by this call will be smaller than that returned
8943** by DBSTATUS_CACHE_USED. ^The highwater mark associated with
8944** SQLITE_DBSTATUS_CACHE_USED_SHARED is always 0.</dd>
8945**
8946** [[SQLITE_DBSTATUS_SCHEMA_USED]] ^(<dt>SQLITE_DBSTATUS_SCHEMA_USED</dt>
8947** <dd>This parameter returns the approximate number of bytes of heap
8948** memory used to store the schema for all databases associated
8949** with the connection - main, temp, and any [ATTACH]-ed databases.)^
8950** ^The full amount of memory used by the schemas is reported, even if the
8951** schema memory is shared with other database connections due to
8952** [shared cache mode] being enabled.
8953** ^The highwater mark associated with SQLITE_DBSTATUS_SCHEMA_USED is always 0.
8954** </dd>
8955**
8956** [[SQLITE_DBSTATUS_STMT_USED]] ^(<dt>SQLITE_DBSTATUS_STMT_USED</dt>
8957** <dd>This parameter returns the approximate number of bytes of heap
8958** and lookaside memory used by all prepared statements associated with
8959** the database connection.)^
8960** ^The highwater mark associated with SQLITE_DBSTATUS_STMT_USED is always 0.
8961** </dd>
8962**
8963** [[SQLITE_DBSTATUS_CACHE_HIT]] ^(<dt>SQLITE_DBSTATUS_CACHE_HIT</dt>
8964** <dd>This parameter returns the number of pager cache hits that have
8965** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_HIT
8966** is always 0.
8967** </dd>
8968**
8969** [[SQLITE_DBSTATUS_CACHE_MISS]] ^(<dt>SQLITE_DBSTATUS_CACHE_MISS</dt>
8970** <dd>This parameter returns the number of pager cache misses that have
8971** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_MISS
8972** is always 0.
8973** </dd>
8974**
8975** [[SQLITE_DBSTATUS_CACHE_WRITE]] ^(<dt>SQLITE_DBSTATUS_CACHE_WRITE</dt>
8976** <dd>This parameter returns the number of dirty cache entries that have
8977** been written to disk. Specifically, the number of pages written to the
8978** wal file in wal mode databases, or the number of pages written to the
8979** database file in rollback mode databases. Any pages written as part of
8980** transaction rollback or database recovery operations are not included.
8981** If an IO or other error occurs while writing a page to disk, the effect
8982** on subsequent SQLITE_DBSTATUS_CACHE_WRITE requests is undefined.)^ ^The
8983** highwater mark associated with SQLITE_DBSTATUS_CACHE_WRITE is always 0.
8984** </dd>
8985**
8986** [[SQLITE_DBSTATUS_CACHE_SPILL]] ^(<dt>SQLITE_DBSTATUS_CACHE_SPILL</dt>
8987** <dd>This parameter returns the number of dirty cache entries that have
8988** been written to disk in the middle of a transaction due to the page
8989** cache overflowing. Transactions are more efficient if they are written
8990** to disk all at once. When pages spill mid-transaction, that introduces
8991** additional overhead. This parameter can be used to help identify
8992** inefficiencies that can be resolved by increasing the cache size.
8993** </dd>
8994**
8995** [[SQLITE_DBSTATUS_DEFERRED_FKS]] ^(<dt>SQLITE_DBSTATUS_DEFERRED_FKS</dt>
8996** <dd>This parameter returns zero for the current value if and only if
8997** all foreign key constraints (deferred or immediate) have been
8998** resolved.)^ ^The highwater mark is always 0.
8999** </dd>
9000** </dl>
9001*/
9002#define SQLITE_DBSTATUS_LOOKASIDE_USED 0
9003#define SQLITE_DBSTATUS_CACHE_USED 1
9004#define SQLITE_DBSTATUS_SCHEMA_USED 2
9005#define SQLITE_DBSTATUS_STMT_USED 3
9006#define SQLITE_DBSTATUS_LOOKASIDE_HIT 4
9007#define SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE 5
9008#define SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL 6
9009#define SQLITE_DBSTATUS_CACHE_HIT 7
9010#define SQLITE_DBSTATUS_CACHE_MISS 8
9011#define SQLITE_DBSTATUS_CACHE_WRITE 9
9012#define SQLITE_DBSTATUS_DEFERRED_FKS 10
9013#define SQLITE_DBSTATUS_CACHE_USED_SHARED 11
9014#define SQLITE_DBSTATUS_CACHE_SPILL 12
9015#define SQLITE_DBSTATUS_MAX 12 /* Largest defined DBSTATUS */
9016
9017
9018/*
9019** CAPI3REF: Prepared Statement Status
9020** METHOD: sqlite3_stmt
9021**
9022** ^(Each prepared statement maintains various
9023** [SQLITE_STMTSTATUS counters] that measure the number
9024** of times it has performed specific operations.)^ These counters can
9025** be used to monitor the performance characteristics of the prepared
9026** statements. For example, if the number of table steps greatly exceeds
9027** the number of table searches or result rows, that would tend to indicate
9028** that the prepared statement is using a full table scan rather than
9029** an index.
9030**
9031** ^(This interface is used to retrieve and reset counter values from
9032** a [prepared statement]. The first argument is the prepared statement
9033** object to be interrogated. The second argument
9034** is an integer code for a specific [SQLITE_STMTSTATUS counter]
9035** to be interrogated.)^
9036** ^The current value of the requested counter is returned.
9037** ^If the resetFlg is true, then the counter is reset to zero after this
9038** interface call returns.
9039**
9040** See also: [sqlite3_status()] and [sqlite3_db_status()].
9041*/
9042SQLITE_API int sqlite3_stmt_status(sqlite3_stmt*, int op,int resetFlg);
9043
9044/*
9045** CAPI3REF: Status Parameters for prepared statements
9046** KEYWORDS: {SQLITE_STMTSTATUS counter} {SQLITE_STMTSTATUS counters}
9047**
9048** These preprocessor macros define integer codes that name counter
9049** values associated with the [sqlite3_stmt_status()] interface.
9050** The meanings of the various counters are as follows:
9051**
9052** <dl>
9053** [[SQLITE_STMTSTATUS_FULLSCAN_STEP]] <dt>SQLITE_STMTSTATUS_FULLSCAN_STEP</dt>
9054** <dd>^This is the number of times that SQLite has stepped forward in
9055** a table as part of a full table scan. Large numbers for this counter
9056** may indicate opportunities for performance improvement through
9057** careful use of indices.</dd>
9058**
9059** [[SQLITE_STMTSTATUS_SORT]] <dt>SQLITE_STMTSTATUS_SORT</dt>
9060** <dd>^This is the number of sort operations that have occurred.
9061** A non-zero value in this counter may indicate an opportunity to
9062** improve performance through careful use of indices.</dd>
9063**
9064** [[SQLITE_STMTSTATUS_AUTOINDEX]] <dt>SQLITE_STMTSTATUS_AUTOINDEX</dt>
9065** <dd>^This is the number of rows inserted into transient indices that
9066** were created automatically in order to help joins run faster.
9067** A non-zero value in this counter may indicate an opportunity to
9068** improve performance by adding permanent indices that do not
9069** need to be reinitialized each time the statement is run.</dd>
9070**
9071** [[SQLITE_STMTSTATUS_VM_STEP]] <dt>SQLITE_STMTSTATUS_VM_STEP</dt>
9072** <dd>^This is the number of virtual machine operations executed
9073** by the prepared statement if that number is less than or equal
9074** to 2147483647. The number of virtual machine operations can be
9075** used as a proxy for the total work done by the prepared statement.
9076** If the number of virtual machine operations exceeds 2147483647
9077** then the value returned by this statement status code is undefined.</dd>
9078**
9079** [[SQLITE_STMTSTATUS_REPREPARE]] <dt>SQLITE_STMTSTATUS_REPREPARE</dt>
9080** <dd>^This is the number of times that the prepare statement has been
9081** automatically regenerated due to schema changes or changes to
9082** [bound parameters] that might affect the query plan.</dd>
9083**
9084** [[SQLITE_STMTSTATUS_RUN]] <dt>SQLITE_STMTSTATUS_RUN</dt>
9085** <dd>^This is the number of times that the prepared statement has
9086** been run. A single "run" for the purposes of this counter is one
9087** or more calls to [sqlite3_step()] followed by a call to [sqlite3_reset()].
9088** The counter is incremented on the first [sqlite3_step()] call of each
9089** cycle.</dd>
9090**
9091** [[SQLITE_STMTSTATUS_FILTER_MISS]]
9092** [[SQLITE_STMTSTATUS_FILTER HIT]]
9093** <dt>SQLITE_STMTSTATUS_FILTER_HIT<br>
9094** SQLITE_STMTSTATUS_FILTER_MISS</dt>
9095** <dd>^SQLITE_STMTSTATUS_FILTER_HIT is the number of times that a join
9096** step was bypassed because a Bloom filter returned not-found. The
9097** corresponding SQLITE_STMTSTATUS_FILTER_MISS value is the number of
9098** times that the Bloom filter returned a find, and thus the join step
9099** had to be processed as normal.</dd>
9100**
9101** [[SQLITE_STMTSTATUS_MEMUSED]] <dt>SQLITE_STMTSTATUS_MEMUSED</dt>
9102** <dd>^This is the approximate number of bytes of heap memory
9103** used to store the prepared statement. ^This value is not actually
9104** a counter, and so the resetFlg parameter to sqlite3_stmt_status()
9105** is ignored when the opcode is SQLITE_STMTSTATUS_MEMUSED.
9106** </dd>
9107** </dl>
9108*/
9109#define SQLITE_STMTSTATUS_FULLSCAN_STEP 1
9110#define SQLITE_STMTSTATUS_SORT 2
9111#define SQLITE_STMTSTATUS_AUTOINDEX 3
9112#define SQLITE_STMTSTATUS_VM_STEP 4
9113#define SQLITE_STMTSTATUS_REPREPARE 5
9114#define SQLITE_STMTSTATUS_RUN 6
9115#define SQLITE_STMTSTATUS_FILTER_MISS 7
9116#define SQLITE_STMTSTATUS_FILTER_HIT 8
9117#define SQLITE_STMTSTATUS_MEMUSED 99
9118
9119/*
9120** CAPI3REF: Custom Page Cache Object
9121**
9122** The sqlite3_pcache type is opaque. It is implemented by
9123** the pluggable module. The SQLite core has no knowledge of
9124** its size or internal structure and never deals with the
9125** sqlite3_pcache object except by holding and passing pointers
9126** to the object.
9127**
9128** See [sqlite3_pcache_methods2] for additional information.
9129*/
9130typedef struct sqlite3_pcache sqlite3_pcache;
9131
9132/*
9133** CAPI3REF: Custom Page Cache Object
9134**
9135** The sqlite3_pcache_page object represents a single page in the
9136** page cache. The page cache will allocate instances of this
9137** object. Various methods of the page cache use pointers to instances
9138** of this object as parameters or as their return value.
9139**
9140** See [sqlite3_pcache_methods2] for additional information.
9141*/
9142typedef struct sqlite3_pcache_page sqlite3_pcache_page;
9143struct sqlite3_pcache_page {
9144 void *pBuf; /* The content of the page */
9145 void *pExtra; /* Extra information associated with the page */
9146};
9147
9148/*
9149** CAPI3REF: Application Defined Page Cache.
9150** KEYWORDS: {page cache}
9151**
9152** ^(The [sqlite3_config]([SQLITE_CONFIG_PCACHE2], ...) interface can
9153** register an alternative page cache implementation by passing in an
9154** instance of the sqlite3_pcache_methods2 structure.)^
9155** In many applications, most of the heap memory allocated by
9156** SQLite is used for the page cache.
9157** By implementing a
9158** custom page cache using this API, an application can better control
9159** the amount of memory consumed by SQLite, the way in which
9160** that memory is allocated and released, and the policies used to
9161** determine exactly which parts of a database file are cached and for
9162** how long.
9163**
9164** The alternative page cache mechanism is an
9165** extreme measure that is only needed by the most demanding applications.
9166** The built-in page cache is recommended for most uses.
9167**
9168** ^(The contents of the sqlite3_pcache_methods2 structure are copied to an
9169** internal buffer by SQLite within the call to [sqlite3_config]. Hence
9170** the application may discard the parameter after the call to
9171** [sqlite3_config()] returns.)^
9172**
9173** [[the xInit() page cache method]]
9174** ^(The xInit() method is called once for each effective
9175** call to [sqlite3_initialize()])^
9176** (usually only once during the lifetime of the process). ^(The xInit()
9177** method is passed a copy of the sqlite3_pcache_methods2.pArg value.)^
9178** The intent of the xInit() method is to set up global data structures
9179** required by the custom page cache implementation.
9180** ^(If the xInit() method is NULL, then the
9181** built-in default page cache is used instead of the application defined
9182** page cache.)^
9183**
9184** [[the xShutdown() page cache method]]
9185** ^The xShutdown() method is called by [sqlite3_shutdown()].
9186** It can be used to clean up
9187** any outstanding resources before process shutdown, if required.
9188** ^The xShutdown() method may be NULL.
9189**
9190** ^SQLite automatically serializes calls to the xInit method,
9191** so the xInit method need not be threadsafe. ^The
9192** xShutdown method is only called from [sqlite3_shutdown()] so it does
9193** not need to be threadsafe either. All other methods must be threadsafe
9194** in multithreaded applications.
9195**
9196** ^SQLite will never invoke xInit() more than once without an intervening
9197** call to xShutdown().
9198**
9199** [[the xCreate() page cache methods]]
9200** ^SQLite invokes the xCreate() method to construct a new cache instance.
9201** SQLite will typically create one cache instance for each open database file,
9202** though this is not guaranteed. ^The
9203** first parameter, szPage, is the size in bytes of the pages that must
9204** be allocated by the cache. ^szPage will always be a power of two. ^The
9205** second parameter szExtra is a number of bytes of extra storage
9206** associated with each page cache entry. ^The szExtra parameter will be
9207** a number less than 250. SQLite will use the
9208** extra szExtra bytes on each page to store metadata about the underlying
9209** database page on disk. The value passed into szExtra depends
9210** on the SQLite version, the target platform, and how SQLite was compiled.
9211** ^The third argument to xCreate(), bPurgeable, is true if the cache being
9212** created will be used to cache database pages of a file stored on disk, or
9213** false if it is used for an in-memory database. The cache implementation
9214** does not have to do anything special based upon the value of bPurgeable;
9215** it is purely advisory. ^On a cache where bPurgeable is false, SQLite will
9216** never invoke xUnpin() except to deliberately delete a page.
9217** ^In other words, calls to xUnpin() on a cache with bPurgeable set to
9218** false will always have the "discard" flag set to true.
9219** ^Hence, a cache created with bPurgeable set to false will
9220** never contain any unpinned pages.
9221**
9222** [[the xCachesize() page cache method]]
9223** ^(The xCachesize() method may be called at any time by SQLite to set the
9224** suggested maximum cache-size (number of pages stored) for the cache
9225** instance passed as the first argument. This is the value configured using
9226** the SQLite "[PRAGMA cache_size]" command.)^ As with the bPurgeable
9227** parameter, the implementation is not required to do anything with this
9228** value; it is advisory only.
9229**
9230** [[the xPagecount() page cache methods]]
9231** The xPagecount() method must return the number of pages currently
9232** stored in the cache, both pinned and unpinned.
9233**
9234** [[the xFetch() page cache methods]]
9235** The xFetch() method locates a page in the cache and returns a pointer to
9236** an sqlite3_pcache_page object associated with that page, or a NULL pointer.
9237** The pBuf element of the returned sqlite3_pcache_page object will be a
9238** pointer to a buffer of szPage bytes used to store the content of a
9239** single database page. The pExtra element of sqlite3_pcache_page will be
9240** a pointer to the szExtra bytes of extra storage that SQLite has requested
9241** for each entry in the page cache.
9242**
9243** The page to be fetched is determined by the key. ^The minimum key value
9244** is 1. After it has been retrieved using xFetch, the page is considered
9245** to be "pinned".
9246**
9247** If the requested page is already in the page cache, then the page cache
9248** implementation must return a pointer to the page buffer with its content
9249** intact. If the requested page is not already in the cache, then the
9250** cache implementation should use the value of the createFlag
9251** parameter to help it determine what action to take:
9252**
9253** <table border=1 width=85% align=center>
9254** <tr><th> createFlag <th> Behavior when page is not already in cache
9255** <tr><td> 0 <td> Do not allocate a new page. Return NULL.
9256** <tr><td> 1 <td> Allocate a new page if it is easy and convenient to do so.
9257** Otherwise return NULL.
9258** <tr><td> 2 <td> Make every effort to allocate a new page. Only return
9259** NULL if allocating a new page is effectively impossible.
9260** </table>
9261**
9262** ^(SQLite will normally invoke xFetch() with a createFlag of 0 or 1. SQLite
9263** will only use a createFlag of 2 after a prior call with a createFlag of 1
9264** failed.)^ In between the xFetch() calls, SQLite may
9265** attempt to unpin one or more cache pages by spilling the content of
9266** pinned pages to disk and synching the operating system disk cache.
9267**
9268** [[the xUnpin() page cache method]]
9269** ^xUnpin() is called by SQLite with a pointer to a currently pinned page
9270** as its second argument. If the third parameter, discard, is non-zero,
9271** then the page must be evicted from the cache.
9272** ^If the discard parameter is
9273** zero, then the page may be discarded or retained at the discretion of the
9274** page cache implementation. ^The page cache implementation
9275** may choose to evict unpinned pages at any time.
9276**
9277** The cache must not perform any reference counting. A single
9278** call to xUnpin() unpins the page regardless of the number of prior calls
9279** to xFetch().
9280**
9281** [[the xRekey() page cache methods]]
9282** The xRekey() method is used to change the key value associated with the
9283** page passed as the second argument. If the cache
9284** previously contains an entry associated with newKey, it must be
9285** discarded. ^Any prior cache entry associated with newKey is guaranteed not
9286** to be pinned.
9287**
9288** When SQLite calls the xTruncate() method, the cache must discard all
9289** existing cache entries with page numbers (keys) greater than or equal
9290** to the value of the iLimit parameter passed to xTruncate(). If any
9291** of these pages are pinned, they become implicitly unpinned, meaning that
9292** they can be safely discarded.
9293**
9294** [[the xDestroy() page cache method]]
9295** ^The xDestroy() method is used to delete a cache allocated by xCreate().
9296** All resources associated with the specified cache should be freed. ^After
9297** calling the xDestroy() method, SQLite considers the [sqlite3_pcache*]
9298** handle invalid, and will not use it with any other sqlite3_pcache_methods2
9299** functions.
9300**
9301** [[the xShrink() page cache method]]
9302** ^SQLite invokes the xShrink() method when it wants the page cache to
9303** free up as much of heap memory as possible. The page cache implementation
9304** is not obligated to free any memory, but well-behaved implementations should
9305** do their best.
9306*/
9307typedef struct sqlite3_pcache_methods2 sqlite3_pcache_methods2;
9308struct sqlite3_pcache_methods2 {
9309 int iVersion;
9310 void *pArg;
9311 int (*xInit)(void*);
9312 void (*xShutdown)(void*);
9313 sqlite3_pcache *(*xCreate)(int szPage, int szExtra, int bPurgeable);
9314 void (*xCachesize)(sqlite3_pcache*, int nCachesize);
9315 int (*xPagecount)(sqlite3_pcache*);
9316 sqlite3_pcache_page *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag);
9317 void (*xUnpin)(sqlite3_pcache*, sqlite3_pcache_page*, int discard);
9318 void (*xRekey)(sqlite3_pcache*, sqlite3_pcache_page*,
9319 unsigned oldKey, unsigned newKey);
9320 void (*xTruncate)(sqlite3_pcache*, unsigned iLimit);
9321 void (*xDestroy)(sqlite3_pcache*);
9322 void (*xShrink)(sqlite3_pcache*);
9323};
9324
9325/*
9326** This is the obsolete pcache_methods object that has now been replaced
9327** by sqlite3_pcache_methods2. This object is not used by SQLite. It is
9328** retained in the header file for backwards compatibility only.
9329*/
9330typedef struct sqlite3_pcache_methods sqlite3_pcache_methods;
9331struct sqlite3_pcache_methods {
9332 void *pArg;
9333 int (*xInit)(void*);
9334 void (*xShutdown)(void*);
9335 sqlite3_pcache *(*xCreate)(int szPage, int bPurgeable);
9336 void (*xCachesize)(sqlite3_pcache*, int nCachesize);
9337 int (*xPagecount)(sqlite3_pcache*);
9338 void *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag);
9339 void (*xUnpin)(sqlite3_pcache*, void*, int discard);
9340 void (*xRekey)(sqlite3_pcache*, void*, unsigned oldKey, unsigned newKey);
9341 void (*xTruncate)(sqlite3_pcache*, unsigned iLimit);
9342 void (*xDestroy)(sqlite3_pcache*);
9343};
9344
9345
9346/*
9347** CAPI3REF: Online Backup Object
9348**
9349** The sqlite3_backup object records state information about an ongoing
9350** online backup operation. ^The sqlite3_backup object is created by
9351** a call to [sqlite3_backup_init()] and is destroyed by a call to
9352** [sqlite3_backup_finish()].
9353**
9354** See Also: [Using the SQLite Online Backup API]
9355*/
9356typedef struct sqlite3_backup sqlite3_backup;
9357
9358/*
9359** CAPI3REF: Online Backup API.
9360**
9361** The backup API copies the content of one database into another.
9362** It is useful either for creating backups of databases or
9363** for copying in-memory databases to or from persistent files.
9364**
9365** See Also: [Using the SQLite Online Backup API]
9366**
9367** ^SQLite holds a write transaction open on the destination database file
9368** for the duration of the backup operation.
9369** ^The source database is read-locked only while it is being read;
9370** it is not locked continuously for the entire backup operation.
9371** ^Thus, the backup may be performed on a live source database without
9372** preventing other database connections from
9373** reading or writing to the source database while the backup is underway.
9374**
9375** ^(To perform a backup operation:
9376** <ol>
9377** <li><b>sqlite3_backup_init()</b> is called once to initialize the
9378** backup,
9379** <li><b>sqlite3_backup_step()</b> is called one or more times to transfer
9380** the data between the two databases, and finally
9381** <li><b>sqlite3_backup_finish()</b> is called to release all resources
9382** associated with the backup operation.
9383** </ol>)^
9384** There should be exactly one call to sqlite3_backup_finish() for each
9385** successful call to sqlite3_backup_init().
9386**
9387** [[sqlite3_backup_init()]] <b>sqlite3_backup_init()</b>
9388**
9389** ^The D and N arguments to sqlite3_backup_init(D,N,S,M) are the
9390** [database connection] associated with the destination database
9391** and the database name, respectively.
9392** ^The database name is "main" for the main database, "temp" for the
9393** temporary database, or the name specified after the AS keyword in
9394** an [ATTACH] statement for an attached database.
9395** ^The S and M arguments passed to
9396** sqlite3_backup_init(D,N,S,M) identify the [database connection]
9397** and database name of the source database, respectively.
9398** ^The source and destination [database connections] (parameters S and D)
9399** must be different or else sqlite3_backup_init(D,N,S,M) will fail with
9400** an error.
9401**
9402** ^A call to sqlite3_backup_init() will fail, returning NULL, if
9403** there is already a read or read-write transaction open on the
9404** destination database.
9405**
9406** ^If an error occurs within sqlite3_backup_init(D,N,S,M), then NULL is
9407** returned and an error code and error message are stored in the
9408** destination [database connection] D.
9409** ^The error code and message for the failed call to sqlite3_backup_init()
9410** can be retrieved using the [sqlite3_errcode()], [sqlite3_errmsg()], and/or
9411** [sqlite3_errmsg16()] functions.
9412** ^A successful call to sqlite3_backup_init() returns a pointer to an
9413** [sqlite3_backup] object.
9414** ^The [sqlite3_backup] object may be used with the sqlite3_backup_step() and
9415** sqlite3_backup_finish() functions to perform the specified backup
9416** operation.
9417**
9418** [[sqlite3_backup_step()]] <b>sqlite3_backup_step()</b>
9419**
9420** ^Function sqlite3_backup_step(B,N) will copy up to N pages between
9421** the source and destination databases specified by [sqlite3_backup] object B.
9422** ^If N is negative, all remaining source pages are copied.
9423** ^If sqlite3_backup_step(B,N) successfully copies N pages and there
9424** are still more pages to be copied, then the function returns [SQLITE_OK].
9425** ^If sqlite3_backup_step(B,N) successfully finishes copying all pages
9426** from source to destination, then it returns [SQLITE_DONE].
9427** ^If an error occurs while running sqlite3_backup_step(B,N),
9428** then an [error code] is returned. ^As well as [SQLITE_OK] and
9429** [SQLITE_DONE], a call to sqlite3_backup_step() may return [SQLITE_READONLY],
9430** [SQLITE_NOMEM], [SQLITE_BUSY], [SQLITE_LOCKED], or an
9431** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX] extended error code.
9432**
9433** ^(The sqlite3_backup_step() might return [SQLITE_READONLY] if
9434** <ol>
9435** <li> the destination database was opened read-only, or
9436** <li> the destination database is using write-ahead-log journaling
9437** and the destination and source page sizes differ, or
9438** <li> the destination database is an in-memory database and the
9439** destination and source page sizes differ.
9440** </ol>)^
9441**
9442** ^If sqlite3_backup_step() cannot obtain a required file-system lock, then
9443** the [sqlite3_busy_handler | busy-handler function]
9444** is invoked (if one is specified). ^If the
9445** busy-handler returns non-zero before the lock is available, then
9446** [SQLITE_BUSY] is returned to the caller. ^In this case the call to
9447** sqlite3_backup_step() can be retried later. ^If the source
9448** [database connection]
9449** is being used to write to the source database when sqlite3_backup_step()
9450** is called, then [SQLITE_LOCKED] is returned immediately. ^Again, in this
9451** case the call to sqlite3_backup_step() can be retried later on. ^(If
9452** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX], [SQLITE_NOMEM], or
9453** [SQLITE_READONLY] is returned, then
9454** there is no point in retrying the call to sqlite3_backup_step(). These
9455** errors are considered fatal.)^ The application must accept
9456** that the backup operation has failed and pass the backup operation handle
9457** to the sqlite3_backup_finish() to release associated resources.
9458**
9459** ^The first call to sqlite3_backup_step() obtains an exclusive lock
9460** on the destination file. ^The exclusive lock is not released until either
9461** sqlite3_backup_finish() is called or the backup operation is complete
9462** and sqlite3_backup_step() returns [SQLITE_DONE]. ^Every call to
9463** sqlite3_backup_step() obtains a [shared lock] on the source database that
9464** lasts for the duration of the sqlite3_backup_step() call.
9465** ^Because the source database is not locked between calls to
9466** sqlite3_backup_step(), the source database may be modified mid-way
9467** through the backup process. ^If the source database is modified by an
9468** external process or via a database connection other than the one being
9469** used by the backup operation, then the backup will be automatically
9470** restarted by the next call to sqlite3_backup_step(). ^If the source
9471** database is modified by using the same database connection as is used
9472** by the backup operation, then the backup database is automatically
9473** updated at the same time.
9474**
9475** [[sqlite3_backup_finish()]] <b>sqlite3_backup_finish()</b>
9476**
9477** When sqlite3_backup_step() has returned [SQLITE_DONE], or when the
9478** application wishes to abandon the backup operation, the application
9479** should destroy the [sqlite3_backup] by passing it to sqlite3_backup_finish().
9480** ^The sqlite3_backup_finish() interfaces releases all
9481** resources associated with the [sqlite3_backup] object.
9482** ^If sqlite3_backup_step() has not yet returned [SQLITE_DONE], then any
9483** active write-transaction on the destination database is rolled back.
9484** The [sqlite3_backup] object is invalid
9485** and may not be used following a call to sqlite3_backup_finish().
9486**
9487** ^The value returned by sqlite3_backup_finish is [SQLITE_OK] if no
9488** sqlite3_backup_step() errors occurred, regardless of whether or not
9489** sqlite3_backup_step() completed.
9490** ^If an out-of-memory condition or IO error occurred during any prior
9491** sqlite3_backup_step() call on the same [sqlite3_backup] object, then
9492** sqlite3_backup_finish() returns the corresponding [error code].
9493**
9494** ^A return of [SQLITE_BUSY] or [SQLITE_LOCKED] from sqlite3_backup_step()
9495** is not a permanent error and does not affect the return value of
9496** sqlite3_backup_finish().
9497**
9498** [[sqlite3_backup_remaining()]] [[sqlite3_backup_pagecount()]]
9499** <b>sqlite3_backup_remaining() and sqlite3_backup_pagecount()</b>
9500**
9501** ^The sqlite3_backup_remaining() routine returns the number of pages still
9502** to be backed up at the conclusion of the most recent sqlite3_backup_step().
9503** ^The sqlite3_backup_pagecount() routine returns the total number of pages
9504** in the source database at the conclusion of the most recent
9505** sqlite3_backup_step().
9506** ^(The values returned by these functions are only updated by
9507** sqlite3_backup_step(). If the source database is modified in a way that
9508** changes the size of the source database or the number of pages remaining,
9509** those changes are not reflected in the output of sqlite3_backup_pagecount()
9510** and sqlite3_backup_remaining() until after the next
9511** sqlite3_backup_step().)^
9512**
9513** <b>Concurrent Usage of Database Handles</b>
9514**
9515** ^The source [database connection] may be used by the application for other
9516** purposes while a backup operation is underway or being initialized.
9517** ^If SQLite is compiled and configured to support threadsafe database
9518** connections, then the source database connection may be used concurrently
9519** from within other threads.
9520**
9521** However, the application must guarantee that the destination
9522** [database connection] is not passed to any other API (by any thread) after
9523** sqlite3_backup_init() is called and before the corresponding call to
9524** sqlite3_backup_finish(). SQLite does not currently check to see
9525** if the application incorrectly accesses the destination [database connection]
9526** and so no error code is reported, but the operations may malfunction
9527** nevertheless. Use of the destination database connection while a
9528** backup is in progress might also cause a mutex deadlock.
9529**
9530** If running in [shared cache mode], the application must
9531** guarantee that the shared cache used by the destination database
9532** is not accessed while the backup is running. In practice this means
9533** that the application must guarantee that the disk file being
9534** backed up to is not accessed by any connection within the process,
9535** not just the specific connection that was passed to sqlite3_backup_init().
9536**
9537** The [sqlite3_backup] object itself is partially threadsafe. Multiple
9538** threads may safely make multiple concurrent calls to sqlite3_backup_step().
9539** However, the sqlite3_backup_remaining() and sqlite3_backup_pagecount()
9540** APIs are not strictly speaking threadsafe. If they are invoked at the
9541** same time as another thread is invoking sqlite3_backup_step() it is
9542** possible that they return invalid values.
9543**
9544** <b>Alternatives To Using The Backup API</b>
9545**
9546** Other techniques for safely creating a consistent backup of an SQLite
9547** database include:
9548**
9549** <ul>
9550** <li> The [VACUUM INTO] command.
9551** <li> The [sqlite3_rsync] utility program.
9552** </ul>
9553*/
9554SQLITE_API sqlite3_backup *sqlite3_backup_init(
9555 sqlite3 *pDest, /* Destination database handle */
9556 const char *zDestName, /* Destination database name */
9557 sqlite3 *pSource, /* Source database handle */
9558 const char *zSourceName /* Source database name */
9559);
9560SQLITE_API int sqlite3_backup_step(sqlite3_backup *p, int nPage);
9561SQLITE_API int sqlite3_backup_finish(sqlite3_backup *p);
9562SQLITE_API int sqlite3_backup_remaining(sqlite3_backup *p);
9563SQLITE_API int sqlite3_backup_pagecount(sqlite3_backup *p);
9564
9565/*
9566** CAPI3REF: Unlock Notification
9567** METHOD: sqlite3
9568**
9569** ^When running in shared-cache mode, a database operation may fail with
9570** an [SQLITE_LOCKED] error if the required locks on the shared-cache or
9571** individual tables within the shared-cache cannot be obtained. See
9572** [SQLite Shared-Cache Mode] for a description of shared-cache locking.
9573** ^This API may be used to register a callback that SQLite will invoke
9574** when the connection currently holding the required lock relinquishes it.
9575** ^This API is only available if the library was compiled with the
9576** [SQLITE_ENABLE_UNLOCK_NOTIFY] C-preprocessor symbol defined.
9577**
9578** See Also: [Using the SQLite Unlock Notification Feature].
9579**
9580** ^Shared-cache locks are released when a database connection concludes
9581** its current transaction, either by committing it or rolling it back.
9582**
9583** ^When a connection (known as the blocked connection) fails to obtain a
9584** shared-cache lock and SQLITE_LOCKED is returned to the caller, the
9585** identity of the database connection (the blocking connection) that
9586** has locked the required resource is stored internally. ^After an
9587** application receives an SQLITE_LOCKED error, it may call the
9588** sqlite3_unlock_notify() method with the blocked connection handle as
9589** the first argument to register for a callback that will be invoked
9590** when the blocking connection's current transaction is concluded. ^The
9591** callback is invoked from within the [sqlite3_step] or [sqlite3_close]
9592** call that concludes the blocking connection's transaction.
9593**
9594** ^(If sqlite3_unlock_notify() is called in a multi-threaded application,
9595** there is a chance that the blocking connection will have already
9596** concluded its transaction by the time sqlite3_unlock_notify() is invoked.
9597** If this happens, then the specified callback is invoked immediately,
9598** from within the call to sqlite3_unlock_notify().)^
9599**
9600** ^If the blocked connection is attempting to obtain a write-lock on a
9601** shared-cache table, and more than one other connection currently holds
9602** a read-lock on the same table, then SQLite arbitrarily selects one of
9603** the other connections to use as the blocking connection.
9604**
9605** ^(There may be at most one unlock-notify callback registered by a
9606** blocked connection. If sqlite3_unlock_notify() is called when the
9607** blocked connection already has a registered unlock-notify callback,
9608** then the new callback replaces the old.)^ ^If sqlite3_unlock_notify() is
9609** called with a NULL pointer as its second argument, then any existing
9610** unlock-notify callback is canceled. ^The blocked connection's
9611** unlock-notify callback may also be canceled by closing the blocked
9612** connection using [sqlite3_close()].
9613**
9614** The unlock-notify callback is not reentrant. If an application invokes
9615** any sqlite3_xxx API functions from within an unlock-notify callback, a
9616** crash or deadlock may be the result.
9617**
9618** ^Unless deadlock is detected (see below), sqlite3_unlock_notify() always
9619** returns SQLITE_OK.
9620**
9621** <b>Callback Invocation Details</b>
9622**
9623** When an unlock-notify callback is registered, the application provides a
9624** single void* pointer that is passed to the callback when it is invoked.
9625** However, the signature of the callback function allows SQLite to pass
9626** it an array of void* context pointers. The first argument passed to
9627** an unlock-notify callback is a pointer to an array of void* pointers,
9628** and the second is the number of entries in the array.
9629**
9630** When a blocking connection's transaction is concluded, there may be
9631** more than one blocked connection that has registered for an unlock-notify
9632** callback. ^If two or more such blocked connections have specified the
9633** same callback function, then instead of invoking the callback function
9634** multiple times, it is invoked once with the set of void* context pointers
9635** specified by the blocked connections bundled together into an array.
9636** This gives the application an opportunity to prioritize any actions
9637** related to the set of unblocked database connections.
9638**
9639** <b>Deadlock Detection</b>
9640**
9641** Assuming that after registering for an unlock-notify callback a
9642** database waits for the callback to be issued before taking any further
9643** action (a reasonable assumption), then using this API may cause the
9644** application to deadlock. For example, if connection X is waiting for
9645** connection Y's transaction to be concluded, and similarly connection
9646** Y is waiting on connection X's transaction, then neither connection
9647** will proceed and the system may remain deadlocked indefinitely.
9648**
9649** To avoid this scenario, the sqlite3_unlock_notify() performs deadlock
9650** detection. ^If a given call to sqlite3_unlock_notify() would put the
9651** system in a deadlocked state, then SQLITE_LOCKED is returned and no
9652** unlock-notify callback is registered. The system is said to be in
9653** a deadlocked state if connection A has registered for an unlock-notify
9654** callback on the conclusion of connection B's transaction, and connection
9655** B has itself registered for an unlock-notify callback when connection
9656** A's transaction is concluded. ^Indirect deadlock is also detected, so
9657** the system is also considered to be deadlocked if connection B has
9658** registered for an unlock-notify callback on the conclusion of connection
9659** C's transaction, where connection C is waiting on connection A. ^Any
9660** number of levels of indirection are allowed.
9661**
9662** <b>The "DROP TABLE" Exception</b>
9663**
9664** When a call to [sqlite3_step()] returns SQLITE_LOCKED, it is almost
9665** always appropriate to call sqlite3_unlock_notify(). There is however,
9666** one exception. When executing a "DROP TABLE" or "DROP INDEX" statement,
9667** SQLite checks if there are any currently executing SELECT statements
9668** that belong to the same connection. If there are, SQLITE_LOCKED is
9669** returned. In this case there is no "blocking connection", so invoking
9670** sqlite3_unlock_notify() results in the unlock-notify callback being
9671** invoked immediately. If the application then re-attempts the "DROP TABLE"
9672** or "DROP INDEX" query, an infinite loop might be the result.
9673**
9674** One way around this problem is to check the extended error code returned
9675** by an sqlite3_step() call. ^(If there is a blocking connection, then the
9676** extended error code is set to SQLITE_LOCKED_SHAREDCACHE. Otherwise, in
9677** the special "DROP TABLE/INDEX" case, the extended error code is just
9678** SQLITE_LOCKED.)^
9679*/
9680SQLITE_API int sqlite3_unlock_notify(
9681 sqlite3 *pBlocked, /* Waiting connection */
9682 void (*xNotify)(void **apArg, int nArg), /* Callback function to invoke */
9683 void *pNotifyArg /* Argument to pass to xNotify */
9684);
9685
9686
9687/*
9688** CAPI3REF: String Comparison
9689**
9690** ^The [sqlite3_stricmp()] and [sqlite3_strnicmp()] APIs allow applications
9691** and extensions to compare the contents of two buffers containing UTF-8
9692** strings in a case-independent fashion, using the same definition of "case
9693** independence" that SQLite uses internally when comparing identifiers.
9694*/
9695SQLITE_API int sqlite3_stricmp(const char *, const char *);
9696SQLITE_API int sqlite3_strnicmp(const char *, const char *, int);
9697
9698/*
9699** CAPI3REF: String Globbing
9700*
9701** ^The [sqlite3_strglob(P,X)] interface returns zero if and only if
9702** string X matches the [GLOB] pattern P.
9703** ^The definition of [GLOB] pattern matching used in
9704** [sqlite3_strglob(P,X)] is the same as for the "X GLOB P" operator in the
9705** SQL dialect understood by SQLite. ^The [sqlite3_strglob(P,X)] function
9706** is case sensitive.
9707**
9708** Note that this routine returns zero on a match and non-zero if the strings
9709** do not match, the same as [sqlite3_stricmp()] and [sqlite3_strnicmp()].
9710**
9711** See also: [sqlite3_strlike()].
9712*/
9713SQLITE_API int sqlite3_strglob(const char *zGlob, const char *zStr);
9714
9715/*
9716** CAPI3REF: String LIKE Matching
9717*
9718** ^The [sqlite3_strlike(P,X,E)] interface returns zero if and only if
9719** string X matches the [LIKE] pattern P with escape character E.
9720** ^The definition of [LIKE] pattern matching used in
9721** [sqlite3_strlike(P,X,E)] is the same as for the "X LIKE P ESCAPE E"
9722** operator in the SQL dialect understood by SQLite. ^For "X LIKE P" without
9723** the ESCAPE clause, set the E parameter of [sqlite3_strlike(P,X,E)] to 0.
9724** ^As with the LIKE operator, the [sqlite3_strlike(P,X,E)] function is case
9725** insensitive - equivalent upper and lower case ASCII characters match
9726** one another.
9727**
9728** ^The [sqlite3_strlike(P,X,E)] function matches Unicode characters, though
9729** only ASCII characters are case folded.
9730**
9731** Note that this routine returns zero on a match and non-zero if the strings
9732** do not match, the same as [sqlite3_stricmp()] and [sqlite3_strnicmp()].
9733**
9734** See also: [sqlite3_strglob()].
9735*/
9736SQLITE_API int sqlite3_strlike(const char *zGlob, const char *zStr, unsigned int cEsc);
9737
9738/*
9739** CAPI3REF: Error Logging Interface
9740**
9741** ^The [sqlite3_log()] interface writes a message into the [error log]
9742** established by the [SQLITE_CONFIG_LOG] option to [sqlite3_config()].
9743** ^If logging is enabled, the zFormat string and subsequent arguments are
9744** used with [sqlite3_snprintf()] to generate the final output string.
9745**
9746** The sqlite3_log() interface is intended for use by extensions such as
9747** virtual tables, collating functions, and SQL functions. While there is
9748** nothing to prevent an application from calling sqlite3_log(), doing so
9749** is considered bad form.
9750**
9751** The zFormat string must not be NULL.
9752**
9753** To avoid deadlocks and other threading problems, the sqlite3_log() routine
9754** will not use dynamically allocated memory. The log message is stored in
9755** a fixed-length buffer on the stack. If the log message is longer than
9756** a few hundred characters, it will be truncated to the length of the
9757** buffer.
9758*/
9759SQLITE_API void sqlite3_log(int iErrCode, const char *zFormat, ...);
9760
9761/*
9762** CAPI3REF: Write-Ahead Log Commit Hook
9763** METHOD: sqlite3
9764**
9765** ^The [sqlite3_wal_hook()] function is used to register a callback that
9766** is invoked each time data is committed to a database in wal mode.
9767**
9768** ^(The callback is invoked by SQLite after the commit has taken place and
9769** the associated write-lock on the database released)^, so the implementation
9770** may read, write or [checkpoint] the database as required.
9771**
9772** ^The first parameter passed to the callback function when it is invoked
9773** is a copy of the third parameter passed to sqlite3_wal_hook() when
9774** registering the callback. ^The second is a copy of the database handle.
9775** ^The third parameter is the name of the database that was written to -
9776** either "main" or the name of an [ATTACH]-ed database. ^The fourth parameter
9777** is the number of pages currently in the write-ahead log file,
9778** including those that were just committed.
9779**
9780** The callback function should normally return [SQLITE_OK]. ^If an error
9781** code is returned, that error will propagate back up through the
9782** SQLite code base to cause the statement that provoked the callback
9783** to report an error, though the commit will have still occurred. If the
9784** callback returns [SQLITE_ROW] or [SQLITE_DONE], or if it returns a value
9785** that does not correspond to any valid SQLite error code, the results
9786** are undefined.
9787**
9788** A single database handle may have at most a single write-ahead log callback
9789** registered at one time. ^Calling [sqlite3_wal_hook()] replaces any
9790** previously registered write-ahead log callback. ^The return value is
9791** a copy of the third parameter from the previous call, if any, or 0.
9792** ^Note that the [sqlite3_wal_autocheckpoint()] interface and the
9793** [wal_autocheckpoint pragma] both invoke [sqlite3_wal_hook()] and will
9794** overwrite any prior [sqlite3_wal_hook()] settings.
9795*/
9796SQLITE_API void *sqlite3_wal_hook(
9797 sqlite3*,
9798 int(*)(void *,sqlite3*,const char*,int),
9799 void*
9800);
9801
9802/*
9803** CAPI3REF: Configure an auto-checkpoint
9804** METHOD: sqlite3
9805**
9806** ^The [sqlite3_wal_autocheckpoint(D,N)] is a wrapper around
9807** [sqlite3_wal_hook()] that causes any database on [database connection] D
9808** to automatically [checkpoint]
9809** after committing a transaction if there are N or
9810** more frames in the [write-ahead log] file. ^Passing zero or
9811** a negative value as the nFrame parameter disables automatic
9812** checkpoints entirely.
9813**
9814** ^The callback registered by this function replaces any existing callback
9815** registered using [sqlite3_wal_hook()]. ^Likewise, registering a callback
9816** using [sqlite3_wal_hook()] disables the automatic checkpoint mechanism
9817** configured by this function.
9818**
9819** ^The [wal_autocheckpoint pragma] can be used to invoke this interface
9820** from SQL.
9821**
9822** ^Checkpoints initiated by this mechanism are
9823** [sqlite3_wal_checkpoint_v2|PASSIVE].
9824**
9825** ^Every new [database connection] defaults to having the auto-checkpoint
9826** enabled with a threshold of 1000 or [SQLITE_DEFAULT_WAL_AUTOCHECKPOINT]
9827** pages. The use of this interface
9828** is only necessary if the default setting is found to be suboptimal
9829** for a particular application.
9830*/
9831SQLITE_API int sqlite3_wal_autocheckpoint(sqlite3 *db, int N);
9832
9833/*
9834** CAPI3REF: Checkpoint a database
9835** METHOD: sqlite3
9836**
9837** ^(The sqlite3_wal_checkpoint(D,X) is equivalent to
9838** [sqlite3_wal_checkpoint_v2](D,X,[SQLITE_CHECKPOINT_PASSIVE],0,0).)^
9839**
9840** In brief, sqlite3_wal_checkpoint(D,X) causes the content in the
9841** [write-ahead log] for database X on [database connection] D to be
9842** transferred into the database file and for the write-ahead log to
9843** be reset. See the [checkpointing] documentation for addition
9844** information.
9845**
9846** This interface used to be the only way to cause a checkpoint to
9847** occur. But then the newer and more powerful [sqlite3_wal_checkpoint_v2()]
9848** interface was added. This interface is retained for backwards
9849** compatibility and as a convenience for applications that need to manually
9850** start a callback but which do not need the full power (and corresponding
9851** complication) of [sqlite3_wal_checkpoint_v2()].
9852*/
9853SQLITE_API int sqlite3_wal_checkpoint(sqlite3 *db, const char *zDb);
9854
9855/*
9856** CAPI3REF: Checkpoint a database
9857** METHOD: sqlite3
9858**
9859** ^(The sqlite3_wal_checkpoint_v2(D,X,M,L,C) interface runs a checkpoint
9860** operation on database X of [database connection] D in mode M. Status
9861** information is written back into integers pointed to by L and C.)^
9862** ^(The M parameter must be a valid [checkpoint mode]:)^
9863**
9864** <dl>
9865** <dt>SQLITE_CHECKPOINT_PASSIVE<dd>
9866** ^Checkpoint as many frames as possible without waiting for any database
9867** readers or writers to finish, then sync the database file if all frames
9868** in the log were checkpointed. ^The [busy-handler callback]
9869** is never invoked in the SQLITE_CHECKPOINT_PASSIVE mode.
9870** ^On the other hand, passive mode might leave the checkpoint unfinished
9871** if there are concurrent readers or writers.
9872**
9873** <dt>SQLITE_CHECKPOINT_FULL<dd>
9874** ^This mode blocks (it invokes the
9875** [sqlite3_busy_handler|busy-handler callback]) until there is no
9876** database writer and all readers are reading from the most recent database
9877** snapshot. ^It then checkpoints all frames in the log file and syncs the
9878** database file. ^This mode blocks new database writers while it is pending,
9879** but new database readers are allowed to continue unimpeded.
9880**
9881** <dt>SQLITE_CHECKPOINT_RESTART<dd>
9882** ^This mode works the same way as SQLITE_CHECKPOINT_FULL with the addition
9883** that after checkpointing the log file it blocks (calls the
9884** [busy-handler callback])
9885** until all readers are reading from the database file only. ^This ensures
9886** that the next writer will restart the log file from the beginning.
9887** ^Like SQLITE_CHECKPOINT_FULL, this mode blocks new
9888** database writer attempts while it is pending, but does not impede readers.
9889**
9890** <dt>SQLITE_CHECKPOINT_TRUNCATE<dd>
9891** ^This mode works the same way as SQLITE_CHECKPOINT_RESTART with the
9892** addition that it also truncates the log file to zero bytes just prior
9893** to a successful return.
9894** </dl>
9895**
9896** ^If pnLog is not NULL, then *pnLog is set to the total number of frames in
9897** the log file or to -1 if the checkpoint could not run because
9898** of an error or because the database is not in [WAL mode]. ^If pnCkpt is not
9899** NULL,then *pnCkpt is set to the total number of checkpointed frames in the
9900** log file (including any that were already checkpointed before the function
9901** was called) or to -1 if the checkpoint could not run due to an error or
9902** because the database is not in WAL mode. ^Note that upon successful
9903** completion of an SQLITE_CHECKPOINT_TRUNCATE, the log file will have been
9904** truncated to zero bytes and so both *pnLog and *pnCkpt will be set to zero.
9905**
9906** ^All calls obtain an exclusive "checkpoint" lock on the database file. ^If
9907** any other process is running a checkpoint operation at the same time, the
9908** lock cannot be obtained and SQLITE_BUSY is returned. ^Even if there is a
9909** busy-handler configured, it will not be invoked in this case.
9910**
9911** ^The SQLITE_CHECKPOINT_FULL, RESTART and TRUNCATE modes also obtain the
9912** exclusive "writer" lock on the database file. ^If the writer lock cannot be
9913** obtained immediately, and a busy-handler is configured, it is invoked and
9914** the writer lock retried until either the busy-handler returns 0 or the lock
9915** is successfully obtained. ^The busy-handler is also invoked while waiting for
9916** database readers as described above. ^If the busy-handler returns 0 before
9917** the writer lock is obtained or while waiting for database readers, the
9918** checkpoint operation proceeds from that point in the same way as
9919** SQLITE_CHECKPOINT_PASSIVE - checkpointing as many frames as possible
9920** without blocking any further. ^SQLITE_BUSY is returned in this case.
9921**
9922** ^If parameter zDb is NULL or points to a zero length string, then the
9923** specified operation is attempted on all WAL databases [attached] to
9924** [database connection] db. In this case the
9925** values written to output parameters *pnLog and *pnCkpt are undefined. ^If
9926** an SQLITE_BUSY error is encountered when processing one or more of the
9927** attached WAL databases, the operation is still attempted on any remaining
9928** attached databases and SQLITE_BUSY is returned at the end. ^If any other
9929** error occurs while processing an attached database, processing is abandoned
9930** and the error code is returned to the caller immediately. ^If no error
9931** (SQLITE_BUSY or otherwise) is encountered while processing the attached
9932** databases, SQLITE_OK is returned.
9933**
9934** ^If database zDb is the name of an attached database that is not in WAL
9935** mode, SQLITE_OK is returned and both *pnLog and *pnCkpt set to -1. ^If
9936** zDb is not NULL (or a zero length string) and is not the name of any
9937** attached database, SQLITE_ERROR is returned to the caller.
9938**
9939** ^Unless it returns SQLITE_MISUSE,
9940** the sqlite3_wal_checkpoint_v2() interface
9941** sets the error information that is queried by
9942** [sqlite3_errcode()] and [sqlite3_errmsg()].
9943**
9944** ^The [PRAGMA wal_checkpoint] command can be used to invoke this interface
9945** from SQL.
9946*/
9947SQLITE_API int sqlite3_wal_checkpoint_v2(
9948 sqlite3 *db, /* Database handle */
9949 const char *zDb, /* Name of attached database (or NULL) */
9950 int eMode, /* SQLITE_CHECKPOINT_* value */
9951 int *pnLog, /* OUT: Size of WAL log in frames */
9952 int *pnCkpt /* OUT: Total number of frames checkpointed */
9953);
9954
9955/*
9956** CAPI3REF: Checkpoint Mode Values
9957** KEYWORDS: {checkpoint mode}
9958**
9959** These constants define all valid values for the "checkpoint mode" passed
9960** as the third parameter to the [sqlite3_wal_checkpoint_v2()] interface.
9961** See the [sqlite3_wal_checkpoint_v2()] documentation for details on the
9962** meaning of each of these checkpoint modes.
9963*/
9964#define SQLITE_CHECKPOINT_PASSIVE 0 /* Do as much as possible w/o blocking */
9965#define SQLITE_CHECKPOINT_FULL 1 /* Wait for writers, then checkpoint */
9966#define SQLITE_CHECKPOINT_RESTART 2 /* Like FULL but wait for readers */
9967#define SQLITE_CHECKPOINT_TRUNCATE 3 /* Like RESTART but also truncate WAL */
9968
9969/*
9970** CAPI3REF: Virtual Table Interface Configuration
9971**
9972** This function may be called by either the [xConnect] or [xCreate] method
9973** of a [virtual table] implementation to configure
9974** various facets of the virtual table interface.
9975**
9976** If this interface is invoked outside the context of an xConnect or
9977** xCreate virtual table method then the behavior is undefined.
9978**
9979** In the call sqlite3_vtab_config(D,C,...) the D parameter is the
9980** [database connection] in which the virtual table is being created and
9981** which is passed in as the first argument to the [xConnect] or [xCreate]
9982** method that is invoking sqlite3_vtab_config(). The C parameter is one
9983** of the [virtual table configuration options]. The presence and meaning
9984** of parameters after C depend on which [virtual table configuration option]
9985** is used.
9986*/
9987SQLITE_API int sqlite3_vtab_config(sqlite3*, int op, ...);
9988
9989/*
9990** CAPI3REF: Virtual Table Configuration Options
9991** KEYWORDS: {virtual table configuration options}
9992** KEYWORDS: {virtual table configuration option}
9993**
9994** These macros define the various options to the
9995** [sqlite3_vtab_config()] interface that [virtual table] implementations
9996** can use to customize and optimize their behavior.
9997**
9998** <dl>
9999** [[SQLITE_VTAB_CONSTRAINT_SUPPORT]]
10000** <dt>SQLITE_VTAB_CONSTRAINT_SUPPORT</dt>
10001** <dd>Calls of the form
10002** [sqlite3_vtab_config](db,SQLITE_VTAB_CONSTRAINT_SUPPORT,X) are supported,
10003** where X is an integer. If X is zero, then the [virtual table] whose
10004** [xCreate] or [xConnect] method invoked [sqlite3_vtab_config()] does not
10005** support constraints. In this configuration (which is the default) if
10006** a call to the [xUpdate] method returns [SQLITE_CONSTRAINT], then the entire
10007** statement is rolled back as if [ON CONFLICT | OR ABORT] had been
10008** specified as part of the user's SQL statement, regardless of the actual
10009** ON CONFLICT mode specified.
10010**
10011** If X is non-zero, then the virtual table implementation guarantees
10012** that if [xUpdate] returns [SQLITE_CONSTRAINT], it will do so before
10013** any modifications to internal or persistent data structures have been made.
10014** If the [ON CONFLICT] mode is ABORT, FAIL, IGNORE or ROLLBACK, SQLite
10015** is able to roll back a statement or database transaction, and abandon
10016** or continue processing the current SQL statement as appropriate.
10017** If the ON CONFLICT mode is REPLACE and the [xUpdate] method returns
10018** [SQLITE_CONSTRAINT], SQLite handles this as if the ON CONFLICT mode
10019** had been ABORT.
10020**
10021** Virtual table implementations that are required to handle OR REPLACE
10022** must do so within the [xUpdate] method. If a call to the
10023** [sqlite3_vtab_on_conflict()] function indicates that the current ON
10024** CONFLICT policy is REPLACE, the virtual table implementation should
10025** silently replace the appropriate rows within the xUpdate callback and
10026** return SQLITE_OK. Or, if this is not possible, it may return
10027** SQLITE_CONSTRAINT, in which case SQLite falls back to OR ABORT
10028** constraint handling.
10029** </dd>
10030**
10031** [[SQLITE_VTAB_DIRECTONLY]]<dt>SQLITE_VTAB_DIRECTONLY</dt>
10032** <dd>Calls of the form
10033** [sqlite3_vtab_config](db,SQLITE_VTAB_DIRECTONLY) from within the
10034** the [xConnect] or [xCreate] methods of a [virtual table] implementation
10035** prohibits that virtual table from being used from within triggers and
10036** views.
10037** </dd>
10038**
10039** [[SQLITE_VTAB_INNOCUOUS]]<dt>SQLITE_VTAB_INNOCUOUS</dt>
10040** <dd>Calls of the form
10041** [sqlite3_vtab_config](db,SQLITE_VTAB_INNOCUOUS) from within the
10042** [xConnect] or [xCreate] methods of a [virtual table] implementation
10043** identify that virtual table as being safe to use from within triggers
10044** and views. Conceptually, the SQLITE_VTAB_INNOCUOUS tag means that the
10045** virtual table can do no serious harm even if it is controlled by a
10046** malicious hacker. Developers should avoid setting the SQLITE_VTAB_INNOCUOUS
10047** flag unless absolutely necessary.
10048** </dd>
10049**
10050** [[SQLITE_VTAB_USES_ALL_SCHEMAS]]<dt>SQLITE_VTAB_USES_ALL_SCHEMAS</dt>
10051** <dd>Calls of the form
10052** [sqlite3_vtab_config](db,SQLITE_VTAB_USES_ALL_SCHEMA) from within the
10053** the [xConnect] or [xCreate] methods of a [virtual table] implementation
10054** instruct the query planner to begin at least a read transaction on
10055** all schemas ("main", "temp", and any ATTACH-ed databases) whenever the
10056** virtual table is used.
10057** </dd>
10058** </dl>
10059*/
10060#define SQLITE_VTAB_CONSTRAINT_SUPPORT 1
10061#define SQLITE_VTAB_INNOCUOUS 2
10062#define SQLITE_VTAB_DIRECTONLY 3
10063#define SQLITE_VTAB_USES_ALL_SCHEMAS 4
10064
10065/*
10066** CAPI3REF: Determine The Virtual Table Conflict Policy
10067**
10068** This function may only be called from within a call to the [xUpdate] method
10069** of a [virtual table] implementation for an INSERT or UPDATE operation. ^The
10070** value returned is one of [SQLITE_ROLLBACK], [SQLITE_IGNORE], [SQLITE_FAIL],
10071** [SQLITE_ABORT], or [SQLITE_REPLACE], according to the [ON CONFLICT] mode
10072** of the SQL statement that triggered the call to the [xUpdate] method of the
10073** [virtual table].
10074*/
10075SQLITE_API int sqlite3_vtab_on_conflict(sqlite3 *);
10076
10077/*
10078** CAPI3REF: Determine If Virtual Table Column Access Is For UPDATE
10079**
10080** If the sqlite3_vtab_nochange(X) routine is called within the [xColumn]
10081** method of a [virtual table], then it might return true if the
10082** column is being fetched as part of an UPDATE operation during which the
10083** column value will not change. The virtual table implementation can use
10084** this hint as permission to substitute a return value that is less
10085** expensive to compute and that the corresponding
10086** [xUpdate] method understands as a "no-change" value.
10087**
10088** If the [xColumn] method calls sqlite3_vtab_nochange() and finds that
10089** the column is not changed by the UPDATE statement, then the xColumn
10090** method can optionally return without setting a result, without calling
10091** any of the [sqlite3_result_int|sqlite3_result_xxxxx() interfaces].
10092** In that case, [sqlite3_value_nochange(X)] will return true for the
10093** same column in the [xUpdate] method.
10094**
10095** The sqlite3_vtab_nochange() routine is an optimization. Virtual table
10096** implementations should continue to give a correct answer even if the
10097** sqlite3_vtab_nochange() interface were to always return false. In the
10098** current implementation, the sqlite3_vtab_nochange() interface does always
10099** returns false for the enhanced [UPDATE FROM] statement.
10100*/
10101SQLITE_API int sqlite3_vtab_nochange(sqlite3_context*);
10102
10103/*
10104** CAPI3REF: Determine The Collation For a Virtual Table Constraint
10105** METHOD: sqlite3_index_info
10106**
10107** This function may only be called from within a call to the [xBestIndex]
10108** method of a [virtual table]. This function returns a pointer to a string
10109** that is the name of the appropriate collation sequence to use for text
10110** comparisons on the constraint identified by its arguments.
10111**
10112** The first argument must be the pointer to the [sqlite3_index_info] object
10113** that is the first parameter to the xBestIndex() method. The second argument
10114** must be an index into the aConstraint[] array belonging to the
10115** sqlite3_index_info structure passed to xBestIndex.
10116**
10117** Important:
10118** The first parameter must be the same pointer that is passed into the
10119** xBestMethod() method. The first parameter may not be a pointer to a
10120** different [sqlite3_index_info] object, even an exact copy.
10121**
10122** The return value is computed as follows:
10123**
10124** <ol>
10125** <li><p> If the constraint comes from a WHERE clause expression that contains
10126** a [COLLATE operator], then the name of the collation specified by
10127** that COLLATE operator is returned.
10128** <li><p> If there is no COLLATE operator, but the column that is the subject
10129** of the constraint specifies an alternative collating sequence via
10130** a [COLLATE clause] on the column definition within the CREATE TABLE
10131** statement that was passed into [sqlite3_declare_vtab()], then the
10132** name of that alternative collating sequence is returned.
10133** <li><p> Otherwise, "BINARY" is returned.
10134** </ol>
10135*/
10136SQLITE_API const char *sqlite3_vtab_collation(sqlite3_index_info*,int);
10137
10138/*
10139** CAPI3REF: Determine if a virtual table query is DISTINCT
10140** METHOD: sqlite3_index_info
10141**
10142** This API may only be used from within an [xBestIndex|xBestIndex method]
10143** of a [virtual table] implementation. The result of calling this
10144** interface from outside of xBestIndex() is undefined and probably harmful.
10145**
10146** ^The sqlite3_vtab_distinct() interface returns an integer between 0 and
10147** 3. The integer returned by sqlite3_vtab_distinct()
10148** gives the virtual table additional information about how the query
10149** planner wants the output to be ordered. As long as the virtual table
10150** can meet the ordering requirements of the query planner, it may set
10151** the "orderByConsumed" flag.
10152**
10153** <ol><li value="0"><p>
10154** ^If the sqlite3_vtab_distinct() interface returns 0, that means
10155** that the query planner needs the virtual table to return all rows in the
10156** sort order defined by the "nOrderBy" and "aOrderBy" fields of the
10157** [sqlite3_index_info] object. This is the default expectation. If the
10158** virtual table outputs all rows in sorted order, then it is always safe for
10159** the xBestIndex method to set the "orderByConsumed" flag, regardless of
10160** the return value from sqlite3_vtab_distinct().
10161** <li value="1"><p>
10162** ^(If the sqlite3_vtab_distinct() interface returns 1, that means
10163** that the query planner does not need the rows to be returned in sorted order
10164** as long as all rows with the same values in all columns identified by the
10165** "aOrderBy" field are adjacent.)^ This mode is used when the query planner
10166** is doing a GROUP BY.
10167** <li value="2"><p>
10168** ^(If the sqlite3_vtab_distinct() interface returns 2, that means
10169** that the query planner does not need the rows returned in any particular
10170** order, as long as rows with the same values in all columns identified
10171** by "aOrderBy" are adjacent.)^ ^(Furthermore, when two or more rows
10172** contain the same values for all columns identified by "colUsed", all but
10173** one such row may optionally be omitted from the result.)^
10174** The virtual table is not required to omit rows that are duplicates
10175** over the "colUsed" columns, but if the virtual table can do that without
10176** too much extra effort, it could potentially help the query to run faster.
10177** This mode is used for a DISTINCT query.
10178** <li value="3"><p>
10179** ^(If the sqlite3_vtab_distinct() interface returns 3, that means the
10180** virtual table must return rows in the order defined by "aOrderBy" as
10181** if the sqlite3_vtab_distinct() interface had returned 0. However if
10182** two or more rows in the result have the same values for all columns
10183** identified by "colUsed", then all but one such row may optionally be
10184** omitted.)^ Like when the return value is 2, the virtual table
10185** is not required to omit rows that are duplicates over the "colUsed"
10186** columns, but if the virtual table can do that without
10187** too much extra effort, it could potentially help the query to run faster.
10188** This mode is used for queries
10189** that have both DISTINCT and ORDER BY clauses.
10190** </ol>
10191**
10192** <p>The following table summarizes the conditions under which the
10193** virtual table is allowed to set the "orderByConsumed" flag based on
10194** the value returned by sqlite3_vtab_distinct(). This table is a
10195** restatement of the previous four paragraphs:
10196**
10197** <table border=1 cellspacing=0 cellpadding=10 width="90%">
10198** <tr>
10199** <td valign="top">sqlite3_vtab_distinct() return value
10200** <td valign="top">Rows are returned in aOrderBy order
10201** <td valign="top">Rows with the same value in all aOrderBy columns are adjacent
10202** <td valign="top">Duplicates over all colUsed columns may be omitted
10203** <tr><td>0<td>yes<td>yes<td>no
10204** <tr><td>1<td>no<td>yes<td>no
10205** <tr><td>2<td>no<td>yes<td>yes
10206** <tr><td>3<td>yes<td>yes<td>yes
10207** </table>
10208**
10209** ^For the purposes of comparing virtual table output values to see if the
10210** values are the same value for sorting purposes, two NULL values are considered
10211** to be the same. In other words, the comparison operator is "IS"
10212** (or "IS NOT DISTINCT FROM") and not "==".
10213**
10214** If a virtual table implementation is unable to meet the requirements
10215** specified above, then it must not set the "orderByConsumed" flag in the
10216** [sqlite3_index_info] object or an incorrect answer may result.
10217**
10218** ^A virtual table implementation is always free to return rows in any order
10219** it wants, as long as the "orderByConsumed" flag is not set. ^When the
10220** "orderByConsumed" flag is unset, the query planner will add extra
10221** [bytecode] to ensure that the final results returned by the SQL query are
10222** ordered correctly. The use of the "orderByConsumed" flag and the
10223** sqlite3_vtab_distinct() interface is merely an optimization. ^Careful
10224** use of the sqlite3_vtab_distinct() interface and the "orderByConsumed"
10225** flag might help queries against a virtual table to run faster. Being
10226** overly aggressive and setting the "orderByConsumed" flag when it is not
10227** valid to do so, on the other hand, might cause SQLite to return incorrect
10228** results.
10229*/
10230SQLITE_API int sqlite3_vtab_distinct(sqlite3_index_info*);
10231
10232/*
10233** CAPI3REF: Identify and handle IN constraints in xBestIndex
10234**
10235** This interface may only be used from within an
10236** [xBestIndex|xBestIndex() method] of a [virtual table] implementation.
10237** The result of invoking this interface from any other context is
10238** undefined and probably harmful.
10239**
10240** ^(A constraint on a virtual table of the form
10241** "[IN operator|column IN (...)]" is
10242** communicated to the xBestIndex method as a
10243** [SQLITE_INDEX_CONSTRAINT_EQ] constraint.)^ If xBestIndex wants to use
10244** this constraint, it must set the corresponding
10245** aConstraintUsage[].argvIndex to a positive integer. ^(Then, under
10246** the usual mode of handling IN operators, SQLite generates [bytecode]
10247** that invokes the [xFilter|xFilter() method] once for each value
10248** on the right-hand side of the IN operator.)^ Thus the virtual table
10249** only sees a single value from the right-hand side of the IN operator
10250** at a time.
10251**
10252** In some cases, however, it would be advantageous for the virtual
10253** table to see all values on the right-hand of the IN operator all at
10254** once. The sqlite3_vtab_in() interfaces facilitates this in two ways:
10255**
10256** <ol>
10257** <li><p>
10258** ^A call to sqlite3_vtab_in(P,N,-1) will return true (non-zero)
10259** if and only if the [sqlite3_index_info|P->aConstraint][N] constraint
10260** is an [IN operator] that can be processed all at once. ^In other words,
10261** sqlite3_vtab_in() with -1 in the third argument is a mechanism
10262** by which the virtual table can ask SQLite if all-at-once processing
10263** of the IN operator is even possible.
10264**
10265** <li><p>
10266** ^A call to sqlite3_vtab_in(P,N,F) with F==1 or F==0 indicates
10267** to SQLite that the virtual table does or does not want to process
10268** the IN operator all-at-once, respectively. ^Thus when the third
10269** parameter (F) is non-negative, this interface is the mechanism by
10270** which the virtual table tells SQLite how it wants to process the
10271** IN operator.
10272** </ol>
10273**
10274** ^The sqlite3_vtab_in(P,N,F) interface can be invoked multiple times
10275** within the same xBestIndex method call. ^For any given P,N pair,
10276** the return value from sqlite3_vtab_in(P,N,F) will always be the same
10277** within the same xBestIndex call. ^If the interface returns true
10278** (non-zero), that means that the constraint is an IN operator
10279** that can be processed all-at-once. ^If the constraint is not an IN
10280** operator or cannot be processed all-at-once, then the interface returns
10281** false.
10282**
10283** ^(All-at-once processing of the IN operator is selected if both of the
10284** following conditions are met:
10285**
10286** <ol>
10287** <li><p> The P->aConstraintUsage[N].argvIndex value is set to a positive
10288** integer. This is how the virtual table tells SQLite that it wants to
10289** use the N-th constraint.
10290**
10291** <li><p> The last call to sqlite3_vtab_in(P,N,F) for which F was
10292** non-negative had F>=1.
10293** </ol>)^
10294**
10295** ^If either or both of the conditions above are false, then SQLite uses
10296** the traditional one-at-a-time processing strategy for the IN constraint.
10297** ^If both conditions are true, then the argvIndex-th parameter to the
10298** xFilter method will be an [sqlite3_value] that appears to be NULL,
10299** but which can be passed to [sqlite3_vtab_in_first()] and
10300** [sqlite3_vtab_in_next()] to find all values on the right-hand side
10301** of the IN constraint.
10302*/
10303SQLITE_API int sqlite3_vtab_in(sqlite3_index_info*, int iCons, int bHandle);
10304
10305/*
10306** CAPI3REF: Find all elements on the right-hand side of an IN constraint.
10307**
10308** These interfaces are only useful from within the
10309** [xFilter|xFilter() method] of a [virtual table] implementation.
10310** The result of invoking these interfaces from any other context
10311** is undefined and probably harmful.
10312**
10313** The X parameter in a call to sqlite3_vtab_in_first(X,P) or
10314** sqlite3_vtab_in_next(X,P) should be one of the parameters to the
10315** xFilter method which invokes these routines, and specifically
10316** a parameter that was previously selected for all-at-once IN constraint
10317** processing using the [sqlite3_vtab_in()] interface in the
10318** [xBestIndex|xBestIndex method]. ^(If the X parameter is not
10319** an xFilter argument that was selected for all-at-once IN constraint
10320** processing, then these routines return [SQLITE_ERROR].)^
10321**
10322** ^(Use these routines to access all values on the right-hand side
10323** of the IN constraint using code like the following:
10324**
10325** <blockquote><pre>
10326** for(rc=sqlite3_vtab_in_first(pList, &pVal);
10327** rc==SQLITE_OK && pVal;
10328** rc=sqlite3_vtab_in_next(pList, &pVal)
10329** ){
10330** // do something with pVal
10331** }
10332** if( rc!=SQLITE_OK ){
10333** // an error has occurred
10334** }
10335** </pre></blockquote>)^
10336**
10337** ^On success, the sqlite3_vtab_in_first(X,P) and sqlite3_vtab_in_next(X,P)
10338** routines return SQLITE_OK and set *P to point to the first or next value
10339** on the RHS of the IN constraint. ^If there are no more values on the
10340** right hand side of the IN constraint, then *P is set to NULL and these
10341** routines return [SQLITE_DONE]. ^The return value might be
10342** some other value, such as SQLITE_NOMEM, in the event of a malfunction.
10343**
10344** The *ppOut values returned by these routines are only valid until the
10345** next call to either of these routines or until the end of the xFilter
10346** method from which these routines were called. If the virtual table
10347** implementation needs to retain the *ppOut values for longer, it must make
10348** copies. The *ppOut values are [protected sqlite3_value|protected].
10349*/
10350SQLITE_API int sqlite3_vtab_in_first(sqlite3_value *pVal, sqlite3_value **ppOut);
10351SQLITE_API int sqlite3_vtab_in_next(sqlite3_value *pVal, sqlite3_value **ppOut);
10352
10353/*
10354** CAPI3REF: Constraint values in xBestIndex()
10355** METHOD: sqlite3_index_info
10356**
10357** This API may only be used from within the [xBestIndex|xBestIndex method]
10358** of a [virtual table] implementation. The result of calling this interface
10359** from outside of an xBestIndex method are undefined and probably harmful.
10360**
10361** ^When the sqlite3_vtab_rhs_value(P,J,V) interface is invoked from within
10362** the [xBestIndex] method of a [virtual table] implementation, with P being
10363** a copy of the [sqlite3_index_info] object pointer passed into xBestIndex and
10364** J being a 0-based index into P->aConstraint[], then this routine
10365** attempts to set *V to the value of the right-hand operand of
10366** that constraint if the right-hand operand is known. ^If the
10367** right-hand operand is not known, then *V is set to a NULL pointer.
10368** ^The sqlite3_vtab_rhs_value(P,J,V) interface returns SQLITE_OK if
10369** and only if *V is set to a value. ^The sqlite3_vtab_rhs_value(P,J,V)
10370** inteface returns SQLITE_NOTFOUND if the right-hand side of the J-th
10371** constraint is not available. ^The sqlite3_vtab_rhs_value() interface
10372** can return a result code other than SQLITE_OK or SQLITE_NOTFOUND if
10373** something goes wrong.
10374**
10375** The sqlite3_vtab_rhs_value() interface is usually only successful if
10376** the right-hand operand of a constraint is a literal value in the original
10377** SQL statement. If the right-hand operand is an expression or a reference
10378** to some other column or a [host parameter], then sqlite3_vtab_rhs_value()
10379** will probably return [SQLITE_NOTFOUND].
10380**
10381** ^(Some constraints, such as [SQLITE_INDEX_CONSTRAINT_ISNULL] and
10382** [SQLITE_INDEX_CONSTRAINT_ISNOTNULL], have no right-hand operand. For such
10383** constraints, sqlite3_vtab_rhs_value() always returns SQLITE_NOTFOUND.)^
10384**
10385** ^The [sqlite3_value] object returned in *V is a protected sqlite3_value
10386** and remains valid for the duration of the xBestIndex method call.
10387** ^When xBestIndex returns, the sqlite3_value object returned by
10388** sqlite3_vtab_rhs_value() is automatically deallocated.
10389**
10390** The "_rhs_" in the name of this routine is an abbreviation for
10391** "Right-Hand Side".
10392*/
10393SQLITE_API int sqlite3_vtab_rhs_value(sqlite3_index_info*, int, sqlite3_value **ppVal);
10394
10395/*
10396** CAPI3REF: Conflict resolution modes
10397** KEYWORDS: {conflict resolution mode}
10398**
10399** These constants are returned by [sqlite3_vtab_on_conflict()] to
10400** inform a [virtual table] implementation of the [ON CONFLICT] mode
10401** for the SQL statement being evaluated.
10402**
10403** Note that the [SQLITE_IGNORE] constant is also used as a potential
10404** return value from the [sqlite3_set_authorizer()] callback and that
10405** [SQLITE_ABORT] is also a [result code].
10406*/
10407#define SQLITE_ROLLBACK 1
10408/* #define SQLITE_IGNORE 2 // Also used by sqlite3_authorizer() callback */
10409#define SQLITE_FAIL 3
10410/* #define SQLITE_ABORT 4 // Also an error code */
10411#define SQLITE_REPLACE 5
10412
10413/*
10414** CAPI3REF: Prepared Statement Scan Status Opcodes
10415** KEYWORDS: {scanstatus options}
10416**
10417** The following constants can be used for the T parameter to the
10418** [sqlite3_stmt_scanstatus(S,X,T,V)] interface. Each constant designates a
10419** different metric for sqlite3_stmt_scanstatus() to return.
10420**
10421** When the value returned to V is a string, space to hold that string is
10422** managed by the prepared statement S and will be automatically freed when
10423** S is finalized.
10424**
10425** Not all values are available for all query elements. When a value is
10426** not available, the output variable is set to -1 if the value is numeric,
10427** or to NULL if it is a string (SQLITE_SCANSTAT_NAME).
10428**
10429** <dl>
10430** [[SQLITE_SCANSTAT_NLOOP]] <dt>SQLITE_SCANSTAT_NLOOP</dt>
10431** <dd>^The [sqlite3_int64] variable pointed to by the V parameter will be
10432** set to the total number of times that the X-th loop has run.</dd>
10433**
10434** [[SQLITE_SCANSTAT_NVISIT]] <dt>SQLITE_SCANSTAT_NVISIT</dt>
10435** <dd>^The [sqlite3_int64] variable pointed to by the V parameter will be set
10436** to the total number of rows examined by all iterations of the X-th loop.</dd>
10437**
10438** [[SQLITE_SCANSTAT_EST]] <dt>SQLITE_SCANSTAT_EST</dt>
10439** <dd>^The "double" variable pointed to by the V parameter will be set to the
10440** query planner's estimate for the average number of rows output from each
10441** iteration of the X-th loop. If the query planner's estimate was accurate,
10442** then this value will approximate the quotient NVISIT/NLOOP and the
10443** product of this value for all prior loops with the same SELECTID will
10444** be the NLOOP value for the current loop.</dd>
10445**
10446** [[SQLITE_SCANSTAT_NAME]] <dt>SQLITE_SCANSTAT_NAME</dt>
10447** <dd>^The "const char *" variable pointed to by the V parameter will be set
10448** to a zero-terminated UTF-8 string containing the name of the index or table
10449** used for the X-th loop.</dd>
10450**
10451** [[SQLITE_SCANSTAT_EXPLAIN]] <dt>SQLITE_SCANSTAT_EXPLAIN</dt>
10452** <dd>^The "const char *" variable pointed to by the V parameter will be set
10453** to a zero-terminated UTF-8 string containing the [EXPLAIN QUERY PLAN]
10454** description for the X-th loop.</dd>
10455**
10456** [[SQLITE_SCANSTAT_SELECTID]] <dt>SQLITE_SCANSTAT_SELECTID</dt>
10457** <dd>^The "int" variable pointed to by the V parameter will be set to the
10458** id for the X-th query plan element. The id value is unique within the
10459** statement. The select-id is the same value as is output in the first
10460** column of an [EXPLAIN QUERY PLAN] query.</dd>
10461**
10462** [[SQLITE_SCANSTAT_PARENTID]] <dt>SQLITE_SCANSTAT_PARENTID</dt>
10463** <dd>The "int" variable pointed to by the V parameter will be set to the
10464** id of the parent of the current query element, if applicable, or
10465** to zero if the query element has no parent. This is the same value as
10466** returned in the second column of an [EXPLAIN QUERY PLAN] query.</dd>
10467**
10468** [[SQLITE_SCANSTAT_NCYCLE]] <dt>SQLITE_SCANSTAT_NCYCLE</dt>
10469** <dd>The sqlite3_int64 output value is set to the number of cycles,
10470** according to the processor time-stamp counter, that elapsed while the
10471** query element was being processed. This value is not available for
10472** all query elements - if it is unavailable the output variable is
10473** set to -1.</dd>
10474** </dl>
10475*/
10476#define SQLITE_SCANSTAT_NLOOP 0
10477#define SQLITE_SCANSTAT_NVISIT 1
10478#define SQLITE_SCANSTAT_EST 2
10479#define SQLITE_SCANSTAT_NAME 3
10480#define SQLITE_SCANSTAT_EXPLAIN 4
10481#define SQLITE_SCANSTAT_SELECTID 5
10482#define SQLITE_SCANSTAT_PARENTID 6
10483#define SQLITE_SCANSTAT_NCYCLE 7
10484
10485/*
10486** CAPI3REF: Prepared Statement Scan Status
10487** METHOD: sqlite3_stmt
10488**
10489** These interfaces return information about the predicted and measured
10490** performance for pStmt. Advanced applications can use this
10491** interface to compare the predicted and the measured performance and
10492** issue warnings and/or rerun [ANALYZE] if discrepancies are found.
10493**
10494** Since this interface is expected to be rarely used, it is only
10495** available if SQLite is compiled using the [SQLITE_ENABLE_STMT_SCANSTATUS]
10496** compile-time option.
10497**
10498** The "iScanStatusOp" parameter determines which status information to return.
10499** The "iScanStatusOp" must be one of the [scanstatus options] or the behavior
10500** of this interface is undefined. ^The requested measurement is written into
10501** a variable pointed to by the "pOut" parameter.
10502**
10503** The "flags" parameter must be passed a mask of flags. At present only
10504** one flag is defined - SQLITE_SCANSTAT_COMPLEX. If SQLITE_SCANSTAT_COMPLEX
10505** is specified, then status information is available for all elements
10506** of a query plan that are reported by "EXPLAIN QUERY PLAN" output. If
10507** SQLITE_SCANSTAT_COMPLEX is not specified, then only query plan elements
10508** that correspond to query loops (the "SCAN..." and "SEARCH..." elements of
10509** the EXPLAIN QUERY PLAN output) are available. Invoking API
10510** sqlite3_stmt_scanstatus() is equivalent to calling
10511** sqlite3_stmt_scanstatus_v2() with a zeroed flags parameter.
10512**
10513** Parameter "idx" identifies the specific query element to retrieve statistics
10514** for. Query elements are numbered starting from zero. A value of -1 may
10515** retrieve statistics for the entire query. ^If idx is out of range
10516** - less than -1 or greater than or equal to the total number of query
10517** elements used to implement the statement - a non-zero value is returned and
10518** the variable that pOut points to is unchanged.
10519**
10520** See also: [sqlite3_stmt_scanstatus_reset()]
10521*/
10522SQLITE_API int sqlite3_stmt_scanstatus(
10523 sqlite3_stmt *pStmt, /* Prepared statement for which info desired */
10524 int idx, /* Index of loop to report on */
10525 int iScanStatusOp, /* Information desired. SQLITE_SCANSTAT_* */
10526 void *pOut /* Result written here */
10527);
10528SQLITE_API int sqlite3_stmt_scanstatus_v2(
10529 sqlite3_stmt *pStmt, /* Prepared statement for which info desired */
10530 int idx, /* Index of loop to report on */
10531 int iScanStatusOp, /* Information desired. SQLITE_SCANSTAT_* */
10532 int flags, /* Mask of flags defined below */
10533 void *pOut /* Result written here */
10534);
10535
10536/*
10537** CAPI3REF: Prepared Statement Scan Status
10538** KEYWORDS: {scan status flags}
10539*/
10540#define SQLITE_SCANSTAT_COMPLEX 0x0001
10541
10542/*
10543** CAPI3REF: Zero Scan-Status Counters
10544** METHOD: sqlite3_stmt
10545**
10546** ^Zero all [sqlite3_stmt_scanstatus()] related event counters.
10547**
10548** This API is only available if the library is built with pre-processor
10549** symbol [SQLITE_ENABLE_STMT_SCANSTATUS] defined.
10550*/
10551SQLITE_API void sqlite3_stmt_scanstatus_reset(sqlite3_stmt*);
10552
10553/*
10554** CAPI3REF: Flush caches to disk mid-transaction
10555** METHOD: sqlite3
10556**
10557** ^If a write-transaction is open on [database connection] D when the
10558** [sqlite3_db_cacheflush(D)] interface is invoked, any dirty
10559** pages in the pager-cache that are not currently in use are written out
10560** to disk. A dirty page may be in use if a database cursor created by an
10561** active SQL statement is reading from it, or if it is page 1 of a database
10562** file (page 1 is always "in use"). ^The [sqlite3_db_cacheflush(D)]
10563** interface flushes caches for all schemas - "main", "temp", and
10564** any [attached] databases.
10565**
10566** ^If this function needs to obtain extra database locks before dirty pages
10567** can be flushed to disk, it does so. ^If those locks cannot be obtained
10568** immediately and there is a busy-handler callback configured, it is invoked
10569** in the usual manner. ^If the required lock still cannot be obtained, then
10570** the database is skipped and an attempt made to flush any dirty pages
10571** belonging to the next (if any) database. ^If any databases are skipped
10572** because locks cannot be obtained, but no other error occurs, this
10573** function returns SQLITE_BUSY.
10574**
10575** ^If any other error occurs while flushing dirty pages to disk (for
10576** example an IO error or out-of-memory condition), then processing is
10577** abandoned and an SQLite [error code] is returned to the caller immediately.
10578**
10579** ^Otherwise, if no error occurs, [sqlite3_db_cacheflush()] returns SQLITE_OK.
10580**
10581** ^This function does not set the database handle error code or message
10582** returned by the [sqlite3_errcode()] and [sqlite3_errmsg()] functions.
10583*/
10584SQLITE_API int sqlite3_db_cacheflush(sqlite3*);
10585
10586/*
10587** CAPI3REF: The pre-update hook.
10588** METHOD: sqlite3
10589**
10590** ^These interfaces are only available if SQLite is compiled using the
10591** [SQLITE_ENABLE_PREUPDATE_HOOK] compile-time option.
10592**
10593** ^The [sqlite3_preupdate_hook()] interface registers a callback function
10594** that is invoked prior to each [INSERT], [UPDATE], and [DELETE] operation
10595** on a database table.
10596** ^At most one preupdate hook may be registered at a time on a single
10597** [database connection]; each call to [sqlite3_preupdate_hook()] overrides
10598** the previous setting.
10599** ^The preupdate hook is disabled by invoking [sqlite3_preupdate_hook()]
10600** with a NULL pointer as the second parameter.
10601** ^The third parameter to [sqlite3_preupdate_hook()] is passed through as
10602** the first parameter to callbacks.
10603**
10604** ^The preupdate hook only fires for changes to real database tables; the
10605** preupdate hook is not invoked for changes to [virtual tables] or to
10606** system tables like sqlite_sequence or sqlite_stat1.
10607**
10608** ^The second parameter to the preupdate callback is a pointer to
10609** the [database connection] that registered the preupdate hook.
10610** ^The third parameter to the preupdate callback is one of the constants
10611** [SQLITE_INSERT], [SQLITE_DELETE], or [SQLITE_UPDATE] to identify the
10612** kind of update operation that is about to occur.
10613** ^(The fourth parameter to the preupdate callback is the name of the
10614** database within the database connection that is being modified. This
10615** will be "main" for the main database or "temp" for TEMP tables or
10616** the name given after the AS keyword in the [ATTACH] statement for attached
10617** databases.)^
10618** ^The fifth parameter to the preupdate callback is the name of the
10619** table that is being modified.
10620**
10621** For an UPDATE or DELETE operation on a [rowid table], the sixth
10622** parameter passed to the preupdate callback is the initial [rowid] of the
10623** row being modified or deleted. For an INSERT operation on a rowid table,
10624** or any operation on a WITHOUT ROWID table, the value of the sixth
10625** parameter is undefined. For an INSERT or UPDATE on a rowid table the
10626** seventh parameter is the final rowid value of the row being inserted
10627** or updated. The value of the seventh parameter passed to the callback
10628** function is not defined for operations on WITHOUT ROWID tables, or for
10629** DELETE operations on rowid tables.
10630**
10631** ^The sqlite3_preupdate_hook(D,C,P) function returns the P argument from
10632** the previous call on the same [database connection] D, or NULL for
10633** the first call on D.
10634**
10635** The [sqlite3_preupdate_old()], [sqlite3_preupdate_new()],
10636** [sqlite3_preupdate_count()], and [sqlite3_preupdate_depth()] interfaces
10637** provide additional information about a preupdate event. These routines
10638** may only be called from within a preupdate callback. Invoking any of
10639** these routines from outside of a preupdate callback or with a
10640** [database connection] pointer that is different from the one supplied
10641** to the preupdate callback results in undefined and probably undesirable
10642** behavior.
10643**
10644** ^The [sqlite3_preupdate_count(D)] interface returns the number of columns
10645** in the row that is being inserted, updated, or deleted.
10646**
10647** ^The [sqlite3_preupdate_old(D,N,P)] interface writes into P a pointer to
10648** a [protected sqlite3_value] that contains the value of the Nth column of
10649** the table row before it is updated. The N parameter must be between 0
10650** and one less than the number of columns or the behavior will be
10651** undefined. This must only be used within SQLITE_UPDATE and SQLITE_DELETE
10652** preupdate callbacks; if it is used by an SQLITE_INSERT callback then the
10653** behavior is undefined. The [sqlite3_value] that P points to
10654** will be destroyed when the preupdate callback returns.
10655**
10656** ^The [sqlite3_preupdate_new(D,N,P)] interface writes into P a pointer to
10657** a [protected sqlite3_value] that contains the value of the Nth column of
10658** the table row after it is updated. The N parameter must be between 0
10659** and one less than the number of columns or the behavior will be
10660** undefined. This must only be used within SQLITE_INSERT and SQLITE_UPDATE
10661** preupdate callbacks; if it is used by an SQLITE_DELETE callback then the
10662** behavior is undefined. The [sqlite3_value] that P points to
10663** will be destroyed when the preupdate callback returns.
10664**
10665** ^The [sqlite3_preupdate_depth(D)] interface returns 0 if the preupdate
10666** callback was invoked as a result of a direct insert, update, or delete
10667** operation; or 1 for inserts, updates, or deletes invoked by top-level
10668** triggers; or 2 for changes resulting from triggers called by top-level
10669** triggers; and so forth.
10670**
10671** When the [sqlite3_blob_write()] API is used to update a blob column,
10672** the pre-update hook is invoked with SQLITE_DELETE, because
10673** the new values are not yet available. In this case, when a
10674** callback made with op==SQLITE_DELETE is actually a write using the
10675** sqlite3_blob_write() API, the [sqlite3_preupdate_blobwrite()] returns
10676** the index of the column being written. In other cases, where the
10677** pre-update hook is being invoked for some other reason, including a
10678** regular DELETE, sqlite3_preupdate_blobwrite() returns -1.
10679**
10680** See also: [sqlite3_update_hook()]
10681*/
10682#if defined(SQLITE_ENABLE_PREUPDATE_HOOK)
10683SQLITE_API void *sqlite3_preupdate_hook(
10684 sqlite3 *db,
10685 void(*xPreUpdate)(
10686 void *pCtx, /* Copy of third arg to preupdate_hook() */
10687 sqlite3 *db, /* Database handle */
10688 int op, /* SQLITE_UPDATE, DELETE or INSERT */
10689 char const *zDb, /* Database name */
10690 char const *zName, /* Table name */
10691 sqlite3_int64 iKey1, /* Rowid of row about to be deleted/updated */
10692 sqlite3_int64 iKey2 /* New rowid value (for a rowid UPDATE) */
10693 ),
10694 void*
10695);
10696SQLITE_API int sqlite3_preupdate_old(sqlite3 *, int, sqlite3_value **);
10697SQLITE_API int sqlite3_preupdate_count(sqlite3 *);
10698SQLITE_API int sqlite3_preupdate_depth(sqlite3 *);
10699SQLITE_API int sqlite3_preupdate_new(sqlite3 *, int, sqlite3_value **);
10700SQLITE_API int sqlite3_preupdate_blobwrite(sqlite3 *);
10701#endif
10702
10703/*
10704** CAPI3REF: Low-level system error code
10705** METHOD: sqlite3
10706**
10707** ^Attempt to return the underlying operating system error code or error
10708** number that caused the most recent I/O error or failure to open a file.
10709** The return value is OS-dependent. For example, on unix systems, after
10710** [sqlite3_open_v2()] returns [SQLITE_CANTOPEN], this interface could be
10711** called to get back the underlying "errno" that caused the problem, such
10712** as ENOSPC, EAUTH, EISDIR, and so forth.
10713*/
10714SQLITE_API int sqlite3_system_errno(sqlite3*);
10715
10716/*
10717** CAPI3REF: Database Snapshot
10718** KEYWORDS: {snapshot} {sqlite3_snapshot}
10719**
10720** An instance of the snapshot object records the state of a [WAL mode]
10721** database for some specific point in history.
10722**
10723** In [WAL mode], multiple [database connections] that are open on the
10724** same database file can each be reading a different historical version
10725** of the database file. When a [database connection] begins a read
10726** transaction, that connection sees an unchanging copy of the database
10727** as it existed for the point in time when the transaction first started.
10728** Subsequent changes to the database from other connections are not seen
10729** by the reader until a new read transaction is started.
10730**
10731** The sqlite3_snapshot object records state information about an historical
10732** version of the database file so that it is possible to later open a new read
10733** transaction that sees that historical version of the database rather than
10734** the most recent version.
10735*/
10736typedef struct sqlite3_snapshot {
10737 unsigned char hidden[48];
10738} sqlite3_snapshot;
10739
10740/*
10741** CAPI3REF: Record A Database Snapshot
10742** CONSTRUCTOR: sqlite3_snapshot
10743**
10744** ^The [sqlite3_snapshot_get(D,S,P)] interface attempts to make a
10745** new [sqlite3_snapshot] object that records the current state of
10746** schema S in database connection D. ^On success, the
10747** [sqlite3_snapshot_get(D,S,P)] interface writes a pointer to the newly
10748** created [sqlite3_snapshot] object into *P and returns SQLITE_OK.
10749** If there is not already a read-transaction open on schema S when
10750** this function is called, one is opened automatically.
10751**
10752** If a read-transaction is opened by this function, then it is guaranteed
10753** that the returned snapshot object may not be invalidated by a database
10754** writer or checkpointer until after the read-transaction is closed. This
10755** is not guaranteed if a read-transaction is already open when this
10756** function is called. In that case, any subsequent write or checkpoint
10757** operation on the database may invalidate the returned snapshot handle,
10758** even while the read-transaction remains open.
10759**
10760** The following must be true for this function to succeed. If any of
10761** the following statements are false when sqlite3_snapshot_get() is
10762** called, SQLITE_ERROR is returned. The final value of *P is undefined
10763** in this case.
10764**
10765** <ul>
10766** <li> The database handle must not be in [autocommit mode].
10767**
10768** <li> Schema S of [database connection] D must be a [WAL mode] database.
10769**
10770** <li> There must not be a write transaction open on schema S of database
10771** connection D.
10772**
10773** <li> One or more transactions must have been written to the current wal
10774** file since it was created on disk (by any connection). This means
10775** that a snapshot cannot be taken on a wal mode database with no wal
10776** file immediately after it is first opened. At least one transaction
10777** must be written to it first.
10778** </ul>
10779**
10780** This function may also return SQLITE_NOMEM. If it is called with the
10781** database handle in autocommit mode but fails for some other reason,
10782** whether or not a read transaction is opened on schema S is undefined.
10783**
10784** The [sqlite3_snapshot] object returned from a successful call to
10785** [sqlite3_snapshot_get()] must be freed using [sqlite3_snapshot_free()]
10786** to avoid a memory leak.
10787**
10788** The [sqlite3_snapshot_get()] interface is only available when the
10789** [SQLITE_ENABLE_SNAPSHOT] compile-time option is used.
10790*/
10791SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_get(
10792 sqlite3 *db,
10793 const char *zSchema,
10794 sqlite3_snapshot **ppSnapshot
10795);
10796
10797/*
10798** CAPI3REF: Start a read transaction on an historical snapshot
10799** METHOD: sqlite3_snapshot
10800**
10801** ^The [sqlite3_snapshot_open(D,S,P)] interface either starts a new read
10802** transaction or upgrades an existing one for schema S of
10803** [database connection] D such that the read transaction refers to
10804** historical [snapshot] P, rather than the most recent change to the
10805** database. ^The [sqlite3_snapshot_open()] interface returns SQLITE_OK
10806** on success or an appropriate [error code] if it fails.
10807**
10808** ^In order to succeed, the database connection must not be in
10809** [autocommit mode] when [sqlite3_snapshot_open(D,S,P)] is called. If there
10810** is already a read transaction open on schema S, then the database handle
10811** must have no active statements (SELECT statements that have been passed
10812** to sqlite3_step() but not sqlite3_reset() or sqlite3_finalize()).
10813** SQLITE_ERROR is returned if either of these conditions is violated, or
10814** if schema S does not exist, or if the snapshot object is invalid.
10815**
10816** ^A call to sqlite3_snapshot_open() will fail to open if the specified
10817** snapshot has been overwritten by a [checkpoint]. In this case
10818** SQLITE_ERROR_SNAPSHOT is returned.
10819**
10820** If there is already a read transaction open when this function is
10821** invoked, then the same read transaction remains open (on the same
10822** database snapshot) if SQLITE_ERROR, SQLITE_BUSY or SQLITE_ERROR_SNAPSHOT
10823** is returned. If another error code - for example SQLITE_PROTOCOL or an
10824** SQLITE_IOERR error code - is returned, then the final state of the
10825** read transaction is undefined. If SQLITE_OK is returned, then the
10826** read transaction is now open on database snapshot P.
10827**
10828** ^(A call to [sqlite3_snapshot_open(D,S,P)] will fail if the
10829** database connection D does not know that the database file for
10830** schema S is in [WAL mode]. A database connection might not know
10831** that the database file is in [WAL mode] if there has been no prior
10832** I/O on that database connection, or if the database entered [WAL mode]
10833** after the most recent I/O on the database connection.)^
10834** (Hint: Run "[PRAGMA application_id]" against a newly opened
10835** database connection in order to make it ready to use snapshots.)
10836**
10837** The [sqlite3_snapshot_open()] interface is only available when the
10838** [SQLITE_ENABLE_SNAPSHOT] compile-time option is used.
10839*/
10840SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_open(
10841 sqlite3 *db,
10842 const char *zSchema,
10843 sqlite3_snapshot *pSnapshot
10844);
10845
10846/*
10847** CAPI3REF: Destroy a snapshot
10848** DESTRUCTOR: sqlite3_snapshot
10849**
10850** ^The [sqlite3_snapshot_free(P)] interface destroys [sqlite3_snapshot] P.
10851** The application must eventually free every [sqlite3_snapshot] object
10852** using this routine to avoid a memory leak.
10853**
10854** The [sqlite3_snapshot_free()] interface is only available when the
10855** [SQLITE_ENABLE_SNAPSHOT] compile-time option is used.
10856*/
10857SQLITE_API SQLITE_EXPERIMENTAL void sqlite3_snapshot_free(sqlite3_snapshot*);
10858
10859/*
10860** CAPI3REF: Compare the ages of two snapshot handles.
10861** METHOD: sqlite3_snapshot
10862**
10863** The sqlite3_snapshot_cmp(P1, P2) interface is used to compare the ages
10864** of two valid snapshot handles.
10865**
10866** If the two snapshot handles are not associated with the same database
10867** file, the result of the comparison is undefined.
10868**
10869** Additionally, the result of the comparison is only valid if both of the
10870** snapshot handles were obtained by calling sqlite3_snapshot_get() since the
10871** last time the wal file was deleted. The wal file is deleted when the
10872** database is changed back to rollback mode or when the number of database
10873** clients drops to zero. If either snapshot handle was obtained before the
10874** wal file was last deleted, the value returned by this function
10875** is undefined.
10876**
10877** Otherwise, this API returns a negative value if P1 refers to an older
10878** snapshot than P2, zero if the two handles refer to the same database
10879** snapshot, and a positive value if P1 is a newer snapshot than P2.
10880**
10881** This interface is only available if SQLite is compiled with the
10882** [SQLITE_ENABLE_SNAPSHOT] option.
10883*/
10884SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_cmp(
10885 sqlite3_snapshot *p1,
10886 sqlite3_snapshot *p2
10887);
10888
10889/*
10890** CAPI3REF: Recover snapshots from a wal file
10891** METHOD: sqlite3_snapshot
10892**
10893** If a [WAL file] remains on disk after all database connections close
10894** (either through the use of the [SQLITE_FCNTL_PERSIST_WAL] [file control]
10895** or because the last process to have the database opened exited without
10896** calling [sqlite3_close()]) and a new connection is subsequently opened
10897** on that database and [WAL file], the [sqlite3_snapshot_open()] interface
10898** will only be able to open the last transaction added to the WAL file
10899** even though the WAL file contains other valid transactions.
10900**
10901** This function attempts to scan the WAL file associated with database zDb
10902** of database handle db and make all valid snapshots available to
10903** sqlite3_snapshot_open(). It is an error if there is already a read
10904** transaction open on the database, or if the database is not a WAL mode
10905** database.
10906**
10907** SQLITE_OK is returned if successful, or an SQLite error code otherwise.
10908**
10909** This interface is only available if SQLite is compiled with the
10910** [SQLITE_ENABLE_SNAPSHOT] option.
10911*/
10912SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_recover(sqlite3 *db, const char *zDb);
10913
10914/*
10915** CAPI3REF: Serialize a database
10916**
10917** The sqlite3_serialize(D,S,P,F) interface returns a pointer to
10918** memory that is a serialization of the S database on
10919** [database connection] D. If S is a NULL pointer, the main database is used.
10920** If P is not a NULL pointer, then the size of the database in bytes
10921** is written into *P.
10922**
10923** For an ordinary on-disk database file, the serialization is just a
10924** copy of the disk file. For an in-memory database or a "TEMP" database,
10925** the serialization is the same sequence of bytes which would be written
10926** to disk if that database were backed up to disk.
10927**
10928** The usual case is that sqlite3_serialize() copies the serialization of
10929** the database into memory obtained from [sqlite3_malloc64()] and returns
10930** a pointer to that memory. The caller is responsible for freeing the
10931** returned value to avoid a memory leak. However, if the F argument
10932** contains the SQLITE_SERIALIZE_NOCOPY bit, then no memory allocations
10933** are made, and the sqlite3_serialize() function will return a pointer
10934** to the contiguous memory representation of the database that SQLite
10935** is currently using for that database, or NULL if no such contiguous
10936** memory representation of the database exists. A contiguous memory
10937** representation of the database will usually only exist if there has
10938** been a prior call to [sqlite3_deserialize(D,S,...)] with the same
10939** values of D and S.
10940** The size of the database is written into *P even if the
10941** SQLITE_SERIALIZE_NOCOPY bit is set but no contiguous copy
10942** of the database exists.
10943**
10944** After the call, if the SQLITE_SERIALIZE_NOCOPY bit had been set,
10945** the returned buffer content will remain accessible and unchanged
10946** until either the next write operation on the connection or when
10947** the connection is closed, and applications must not modify the
10948** buffer. If the bit had been clear, the returned buffer will not
10949** be accessed by SQLite after the call.
10950**
10951** A call to sqlite3_serialize(D,S,P,F) might return NULL even if the
10952** SQLITE_SERIALIZE_NOCOPY bit is omitted from argument F if a memory
10953** allocation error occurs.
10954**
10955** This interface is omitted if SQLite is compiled with the
10956** [SQLITE_OMIT_DESERIALIZE] option.
10957*/
10958SQLITE_API unsigned char *sqlite3_serialize(
10959 sqlite3 *db, /* The database connection */
10960 const char *zSchema, /* Which DB to serialize. ex: "main", "temp", ... */
10961 sqlite3_int64 *piSize, /* Write size of the DB here, if not NULL */
10962 unsigned int mFlags /* Zero or more SQLITE_SERIALIZE_* flags */
10963);
10964
10965/*
10966** CAPI3REF: Flags for sqlite3_serialize
10967**
10968** Zero or more of the following constants can be OR-ed together for
10969** the F argument to [sqlite3_serialize(D,S,P,F)].
10970**
10971** SQLITE_SERIALIZE_NOCOPY means that [sqlite3_serialize()] will return
10972** a pointer to contiguous in-memory database that it is currently using,
10973** without making a copy of the database. If SQLite is not currently using
10974** a contiguous in-memory database, then this option causes
10975** [sqlite3_serialize()] to return a NULL pointer. SQLite will only be
10976** using a contiguous in-memory database if it has been initialized by a
10977** prior call to [sqlite3_deserialize()].
10978*/
10979#define SQLITE_SERIALIZE_NOCOPY 0x001 /* Do no memory allocations */
10980
10981/*
10982** CAPI3REF: Deserialize a database
10983**
10984** The sqlite3_deserialize(D,S,P,N,M,F) interface causes the
10985** [database connection] D to disconnect from database S and then
10986** reopen S as an in-memory database based on the serialization contained
10987** in P. The serialized database P is N bytes in size. M is the size of
10988** the buffer P, which might be larger than N. If M is larger than N, and
10989** the SQLITE_DESERIALIZE_READONLY bit is not set in F, then SQLite is
10990** permitted to add content to the in-memory database as long as the total
10991** size does not exceed M bytes.
10992**
10993** If the SQLITE_DESERIALIZE_FREEONCLOSE bit is set in F, then SQLite will
10994** invoke sqlite3_free() on the serialization buffer when the database
10995** connection closes. If the SQLITE_DESERIALIZE_RESIZEABLE bit is set, then
10996** SQLite will try to increase the buffer size using sqlite3_realloc64()
10997** if writes on the database cause it to grow larger than M bytes.
10998**
10999** Applications must not modify the buffer P or invalidate it before
11000** the database connection D is closed.
11001**
11002** The sqlite3_deserialize() interface will fail with SQLITE_BUSY if the
11003** database is currently in a read transaction or is involved in a backup
11004** operation.
11005**
11006** It is not possible to deserialize into the TEMP database. If the
11007** S argument to sqlite3_deserialize(D,S,P,N,M,F) is "temp" then the
11008** function returns SQLITE_ERROR.
11009**
11010** The deserialized database should not be in [WAL mode]. If the database
11011** is in WAL mode, then any attempt to use the database file will result
11012** in an [SQLITE_CANTOPEN] error. The application can set the
11013** [file format version numbers] (bytes 18 and 19) of the input database P
11014** to 0x01 prior to invoking sqlite3_deserialize(D,S,P,N,M,F) to force the
11015** database file into rollback mode and work around this limitation.
11016**
11017** If sqlite3_deserialize(D,S,P,N,M,F) fails for any reason and if the
11018** SQLITE_DESERIALIZE_FREEONCLOSE bit is set in argument F, then
11019** [sqlite3_free()] is invoked on argument P prior to returning.
11020**
11021** This interface is omitted if SQLite is compiled with the
11022** [SQLITE_OMIT_DESERIALIZE] option.
11023*/
11024SQLITE_API int sqlite3_deserialize(
11025 sqlite3 *db, /* The database connection */
11026 const char *zSchema, /* Which DB to reopen with the deserialization */
11027 unsigned char *pData, /* The serialized database content */
11028 sqlite3_int64 szDb, /* Number of bytes in the deserialization */
11029 sqlite3_int64 szBuf, /* Total size of buffer pData[] */
11030 unsigned mFlags /* Zero or more SQLITE_DESERIALIZE_* flags */
11031);
11032
11033/*
11034** CAPI3REF: Flags for sqlite3_deserialize()
11035**
11036** The following are allowed values for the 6th argument (the F argument) to
11037** the [sqlite3_deserialize(D,S,P,N,M,F)] interface.
11038**
11039** The SQLITE_DESERIALIZE_FREEONCLOSE means that the database serialization
11040** in the P argument is held in memory obtained from [sqlite3_malloc64()]
11041** and that SQLite should take ownership of this memory and automatically
11042** free it when it has finished using it. Without this flag, the caller
11043** is responsible for freeing any dynamically allocated memory.
11044**
11045** The SQLITE_DESERIALIZE_RESIZEABLE flag means that SQLite is allowed to
11046** grow the size of the database using calls to [sqlite3_realloc64()]. This
11047** flag should only be used if SQLITE_DESERIALIZE_FREEONCLOSE is also used.
11048** Without this flag, the deserialized database cannot increase in size beyond
11049** the number of bytes specified by the M parameter.
11050**
11051** The SQLITE_DESERIALIZE_READONLY flag means that the deserialized database
11052** should be treated as read-only.
11053*/
11054#define SQLITE_DESERIALIZE_FREEONCLOSE 1 /* Call sqlite3_free() on close */
11055#define SQLITE_DESERIALIZE_RESIZEABLE 2 /* Resize using sqlite3_realloc64() */
11056#define SQLITE_DESERIALIZE_READONLY 4 /* Database is read-only */
11057
11058/*
11059** Undo the hack that converts floating point types to integer for
11060** builds on processors without floating point support.
11061*/
11062#ifdef SQLITE_OMIT_FLOATING_POINT
11063# undef double
11064#endif
11065
11066#if defined(__wasi__)
11067# undef SQLITE_WASI
11068# define SQLITE_WASI 1
11069# ifndef SQLITE_OMIT_LOAD_EXTENSION
11070# define SQLITE_OMIT_LOAD_EXTENSION
11071# endif
11072# ifndef SQLITE_THREADSAFE
11073# define SQLITE_THREADSAFE 0
11074# endif
11075#endif
11076
11077#ifdef __cplusplus
11078} /* End of the 'extern "C"' block */
11079#endif
11080/* #endif for SQLITE3_H will be added by mksqlite3.tcl */
11081
11082/******** Begin file sqlite3rtree.h *********/
11083/*
11084** 2010 August 30
11085**
11086** The author disclaims copyright to this source code. In place of
11087** a legal notice, here is a blessing:
11088**
11089** May you do good and not evil.
11090** May you find forgiveness for yourself and forgive others.
11091** May you share freely, never taking more than you give.
11092**
11093*************************************************************************
11094*/
11095
11096#ifndef _SQLITE3RTREE_H_
11097#define _SQLITE3RTREE_H_
11098
11099
11100#ifdef __cplusplus
11101extern "C" {
11102#endif
11103
11104typedef struct sqlite3_rtree_geometry sqlite3_rtree_geometry;
11105typedef struct sqlite3_rtree_query_info sqlite3_rtree_query_info;
11106
11107/* The double-precision datatype used by RTree depends on the
11108** SQLITE_RTREE_INT_ONLY compile-time option.
11109*/
11110#ifdef SQLITE_RTREE_INT_ONLY
11111 typedef sqlite3_int64 sqlite3_rtree_dbl;
11112#else
11113 typedef double sqlite3_rtree_dbl;
11114#endif
11115
11116/*
11117** Register a geometry callback named zGeom that can be used as part of an
11118** R-Tree geometry query as follows:
11119**
11120** SELECT ... FROM <rtree> WHERE <rtree col> MATCH $zGeom(... params ...)
11121*/
11122SQLITE_API int sqlite3_rtree_geometry_callback(
11123 sqlite3 *db,
11124 const char *zGeom,
11125 int (*xGeom)(sqlite3_rtree_geometry*, int, sqlite3_rtree_dbl*,int*),
11126 void *pContext
11127);
11128
11129
11130/*
11131** A pointer to a structure of the following type is passed as the first
11132** argument to callbacks registered using rtree_geometry_callback().
11133*/
11134struct sqlite3_rtree_geometry {
11135 void *pContext; /* Copy of pContext passed to s_r_g_c() */
11136 int nParam; /* Size of array aParam[] */
11137 sqlite3_rtree_dbl *aParam; /* Parameters passed to SQL geom function */
11138 void *pUser; /* Callback implementation user data */
11139 void (*xDelUser)(void *); /* Called by SQLite to clean up pUser */
11140};
11141
11142/*
11143** Register a 2nd-generation geometry callback named zScore that can be
11144** used as part of an R-Tree geometry query as follows:
11145**
11146** SELECT ... FROM <rtree> WHERE <rtree col> MATCH $zQueryFunc(... params ...)
11147*/
11148SQLITE_API int sqlite3_rtree_query_callback(
11149 sqlite3 *db,
11150 const char *zQueryFunc,
11151 int (*xQueryFunc)(sqlite3_rtree_query_info*),
11152 void *pContext,
11153 void (*xDestructor)(void*)
11154);
11155
11156
11157/*
11158** A pointer to a structure of the following type is passed as the
11159** argument to scored geometry callback registered using
11160** sqlite3_rtree_query_callback().
11161**
11162** Note that the first 5 fields of this structure are identical to
11163** sqlite3_rtree_geometry. This structure is a subclass of
11164** sqlite3_rtree_geometry.
11165*/
11166struct sqlite3_rtree_query_info {
11167 void *pContext; /* pContext from when function registered */
11168 int nParam; /* Number of function parameters */
11169 sqlite3_rtree_dbl *aParam; /* value of function parameters */
11170 void *pUser; /* callback can use this, if desired */
11171 void (*xDelUser)(void*); /* function to free pUser */
11172 sqlite3_rtree_dbl *aCoord; /* Coordinates of node or entry to check */
11173 unsigned int *anQueue; /* Number of pending entries in the queue */
11174 int nCoord; /* Number of coordinates */
11175 int iLevel; /* Level of current node or entry */
11176 int mxLevel; /* The largest iLevel value in the tree */
11177 sqlite3_int64 iRowid; /* Rowid for current entry */
11178 sqlite3_rtree_dbl rParentScore; /* Score of parent node */
11179 int eParentWithin; /* Visibility of parent node */
11180 int eWithin; /* OUT: Visibility */
11181 sqlite3_rtree_dbl rScore; /* OUT: Write the score here */
11182 /* The following fields are only available in 3.8.11 and later */
11183 sqlite3_value **apSqlParam; /* Original SQL values of parameters */
11184};
11185
11186/*
11187** Allowed values for sqlite3_rtree_query.eWithin and .eParentWithin.
11188*/
11189#define NOT_WITHIN 0 /* Object completely outside of query region */
11190#define PARTLY_WITHIN 1 /* Object partially overlaps query region */
11191#define FULLY_WITHIN 2 /* Object fully contained within query region */
11192
11193
11194#ifdef __cplusplus
11195} /* end of the 'extern "C"' block */
11196#endif
11197
11198#endif /* ifndef _SQLITE3RTREE_H_ */
11199
11200/******** End of sqlite3rtree.h *********/
11201/******** Begin file sqlite3session.h *********/
11202
11203#if !defined(__SQLITESESSION_H_) && defined(SQLITE_ENABLE_SESSION)
11204#define __SQLITESESSION_H_ 1
11205
11206/*
11207** Make sure we can call this stuff from C++.
11208*/
11209#ifdef __cplusplus
11210extern "C" {
11211#endif
11212
11213
11214/*
11215** CAPI3REF: Session Object Handle
11216**
11217** An instance of this object is a [session] that can be used to
11218** record changes to a database.
11219*/
11220typedef struct sqlite3_session sqlite3_session;
11221
11222/*
11223** CAPI3REF: Changeset Iterator Handle
11224**
11225** An instance of this object acts as a cursor for iterating
11226** over the elements of a [changeset] or [patchset].
11227*/
11228typedef struct sqlite3_changeset_iter sqlite3_changeset_iter;
11229
11230/*
11231** CAPI3REF: Create A New Session Object
11232** CONSTRUCTOR: sqlite3_session
11233**
11234** Create a new session object attached to database handle db. If successful,
11235** a pointer to the new object is written to *ppSession and SQLITE_OK is
11236** returned. If an error occurs, *ppSession is set to NULL and an SQLite
11237** error code (e.g. SQLITE_NOMEM) is returned.
11238**
11239** It is possible to create multiple session objects attached to a single
11240** database handle.
11241**
11242** Session objects created using this function should be deleted using the
11243** [sqlite3session_delete()] function before the database handle that they
11244** are attached to is itself closed. If the database handle is closed before
11245** the session object is deleted, then the results of calling any session
11246** module function, including [sqlite3session_delete()] on the session object
11247** are undefined.
11248**
11249** Because the session module uses the [sqlite3_preupdate_hook()] API, it
11250** is not possible for an application to register a pre-update hook on a
11251** database handle that has one or more session objects attached. Nor is
11252** it possible to create a session object attached to a database handle for
11253** which a pre-update hook is already defined. The results of attempting
11254** either of these things are undefined.
11255**
11256** The session object will be used to create changesets for tables in
11257** database zDb, where zDb is either "main", or "temp", or the name of an
11258** attached database. It is not an error if database zDb is not attached
11259** to the database when the session object is created.
11260*/
11261SQLITE_API int sqlite3session_create(
11262 sqlite3 *db, /* Database handle */
11263 const char *zDb, /* Name of db (e.g. "main") */
11264 sqlite3_session **ppSession /* OUT: New session object */
11265);
11266
11267/*
11268** CAPI3REF: Delete A Session Object
11269** DESTRUCTOR: sqlite3_session
11270**
11271** Delete a session object previously allocated using
11272** [sqlite3session_create()]. Once a session object has been deleted, the
11273** results of attempting to use pSession with any other session module
11274** function are undefined.
11275**
11276** Session objects must be deleted before the database handle to which they
11277** are attached is closed. Refer to the documentation for
11278** [sqlite3session_create()] for details.
11279*/
11280SQLITE_API void sqlite3session_delete(sqlite3_session *pSession);
11281
11282/*
11283** CAPI3REF: Configure a Session Object
11284** METHOD: sqlite3_session
11285**
11286** This method is used to configure a session object after it has been
11287** created. At present the only valid values for the second parameter are
11288** [SQLITE_SESSION_OBJCONFIG_SIZE] and [SQLITE_SESSION_OBJCONFIG_ROWID].
11289**
11290*/
11291SQLITE_API int sqlite3session_object_config(sqlite3_session*, int op, void *pArg);
11292
11293/*
11294** CAPI3REF: Options for sqlite3session_object_config
11295**
11296** The following values may passed as the the 2nd parameter to
11297** sqlite3session_object_config().
11298**
11299** <dt>SQLITE_SESSION_OBJCONFIG_SIZE <dd>
11300** This option is used to set, clear or query the flag that enables
11301** the [sqlite3session_changeset_size()] API. Because it imposes some
11302** computational overhead, this API is disabled by default. Argument
11303** pArg must point to a value of type (int). If the value is initially
11304** 0, then the sqlite3session_changeset_size() API is disabled. If it
11305** is greater than 0, then the same API is enabled. Or, if the initial
11306** value is less than zero, no change is made. In all cases the (int)
11307** variable is set to 1 if the sqlite3session_changeset_size() API is
11308** enabled following the current call, or 0 otherwise.
11309**
11310** It is an error (SQLITE_MISUSE) to attempt to modify this setting after
11311** the first table has been attached to the session object.
11312**
11313** <dt>SQLITE_SESSION_OBJCONFIG_ROWID <dd>
11314** This option is used to set, clear or query the flag that enables
11315** collection of data for tables with no explicit PRIMARY KEY.
11316**
11317** Normally, tables with no explicit PRIMARY KEY are simply ignored
11318** by the sessions module. However, if this flag is set, it behaves
11319** as if such tables have a column "_rowid_ INTEGER PRIMARY KEY" inserted
11320** as their leftmost columns.
11321**
11322** It is an error (SQLITE_MISUSE) to attempt to modify this setting after
11323** the first table has been attached to the session object.
11324*/
11325#define SQLITE_SESSION_OBJCONFIG_SIZE 1
11326#define SQLITE_SESSION_OBJCONFIG_ROWID 2
11327
11328/*
11329** CAPI3REF: Enable Or Disable A Session Object
11330** METHOD: sqlite3_session
11331**
11332** Enable or disable the recording of changes by a session object. When
11333** enabled, a session object records changes made to the database. When
11334** disabled - it does not. A newly created session object is enabled.
11335** Refer to the documentation for [sqlite3session_changeset()] for further
11336** details regarding how enabling and disabling a session object affects
11337** the eventual changesets.
11338**
11339** Passing zero to this function disables the session. Passing a value
11340** greater than zero enables it. Passing a value less than zero is a
11341** no-op, and may be used to query the current state of the session.
11342**
11343** The return value indicates the final state of the session object: 0 if
11344** the session is disabled, or 1 if it is enabled.
11345*/
11346SQLITE_API int sqlite3session_enable(sqlite3_session *pSession, int bEnable);
11347
11348/*
11349** CAPI3REF: Set Or Clear the Indirect Change Flag
11350** METHOD: sqlite3_session
11351**
11352** Each change recorded by a session object is marked as either direct or
11353** indirect. A change is marked as indirect if either:
11354**
11355** <ul>
11356** <li> The session object "indirect" flag is set when the change is
11357** made, or
11358** <li> The change is made by an SQL trigger or foreign key action
11359** instead of directly as a result of a users SQL statement.
11360** </ul>
11361**
11362** If a single row is affected by more than one operation within a session,
11363** then the change is considered indirect if all operations meet the criteria
11364** for an indirect change above, or direct otherwise.
11365**
11366** This function is used to set, clear or query the session object indirect
11367** flag. If the second argument passed to this function is zero, then the
11368** indirect flag is cleared. If it is greater than zero, the indirect flag
11369** is set. Passing a value less than zero does not modify the current value
11370** of the indirect flag, and may be used to query the current state of the
11371** indirect flag for the specified session object.
11372**
11373** The return value indicates the final state of the indirect flag: 0 if
11374** it is clear, or 1 if it is set.
11375*/
11376SQLITE_API int sqlite3session_indirect(sqlite3_session *pSession, int bIndirect);
11377
11378/*
11379** CAPI3REF: Attach A Table To A Session Object
11380** METHOD: sqlite3_session
11381**
11382** If argument zTab is not NULL, then it is the name of a table to attach
11383** to the session object passed as the first argument. All subsequent changes
11384** made to the table while the session object is enabled will be recorded. See
11385** documentation for [sqlite3session_changeset()] for further details.
11386**
11387** Or, if argument zTab is NULL, then changes are recorded for all tables
11388** in the database. If additional tables are added to the database (by
11389** executing "CREATE TABLE" statements) after this call is made, changes for
11390** the new tables are also recorded.
11391**
11392** Changes can only be recorded for tables that have a PRIMARY KEY explicitly
11393** defined as part of their CREATE TABLE statement. It does not matter if the
11394** PRIMARY KEY is an "INTEGER PRIMARY KEY" (rowid alias) or not. The PRIMARY
11395** KEY may consist of a single column, or may be a composite key.
11396**
11397** It is not an error if the named table does not exist in the database. Nor
11398** is it an error if the named table does not have a PRIMARY KEY. However,
11399** no changes will be recorded in either of these scenarios.
11400**
11401** Changes are not recorded for individual rows that have NULL values stored
11402** in one or more of their PRIMARY KEY columns.
11403**
11404** SQLITE_OK is returned if the call completes without error. Or, if an error
11405** occurs, an SQLite error code (e.g. SQLITE_NOMEM) is returned.
11406**
11407** <h3>Special sqlite_stat1 Handling</h3>
11408**
11409** As of SQLite version 3.22.0, the "sqlite_stat1" table is an exception to
11410** some of the rules above. In SQLite, the schema of sqlite_stat1 is:
11411** <pre>
11412** CREATE TABLE sqlite_stat1(tbl,idx,stat)
11413** </pre>
11414**
11415** Even though sqlite_stat1 does not have a PRIMARY KEY, changes are
11416** recorded for it as if the PRIMARY KEY is (tbl,idx). Additionally, changes
11417** are recorded for rows for which (idx IS NULL) is true. However, for such
11418** rows a zero-length blob (SQL value X'') is stored in the changeset or
11419** patchset instead of a NULL value. This allows such changesets to be
11420** manipulated by legacy implementations of sqlite3changeset_invert(),
11421** concat() and similar.
11422**
11423** The sqlite3changeset_apply() function automatically converts the
11424** zero-length blob back to a NULL value when updating the sqlite_stat1
11425** table. However, if the application calls sqlite3changeset_new(),
11426** sqlite3changeset_old() or sqlite3changeset_conflict on a changeset
11427** iterator directly (including on a changeset iterator passed to a
11428** conflict-handler callback) then the X'' value is returned. The application
11429** must translate X'' to NULL itself if required.
11430**
11431** Legacy (older than 3.22.0) versions of the sessions module cannot capture
11432** changes made to the sqlite_stat1 table. Legacy versions of the
11433** sqlite3changeset_apply() function silently ignore any modifications to the
11434** sqlite_stat1 table that are part of a changeset or patchset.
11435*/
11436SQLITE_API int sqlite3session_attach(
11437 sqlite3_session *pSession, /* Session object */
11438 const char *zTab /* Table name */
11439);
11440
11441/*
11442** CAPI3REF: Set a table filter on a Session Object.
11443** METHOD: sqlite3_session
11444**
11445** The second argument (xFilter) is the "filter callback". For changes to rows
11446** in tables that are not attached to the Session object, the filter is called
11447** to determine whether changes to the table's rows should be tracked or not.
11448** If xFilter returns 0, changes are not tracked. Note that once a table is
11449** attached, xFilter will not be called again.
11450*/
11451SQLITE_API void sqlite3session_table_filter(
11452 sqlite3_session *pSession, /* Session object */
11453 int(*xFilter)(
11454 void *pCtx, /* Copy of third arg to _filter_table() */
11455 const char *zTab /* Table name */
11456 ),
11457 void *pCtx /* First argument passed to xFilter */
11458);
11459
11460/*
11461** CAPI3REF: Generate A Changeset From A Session Object
11462** METHOD: sqlite3_session
11463**
11464** Obtain a changeset containing changes to the tables attached to the
11465** session object passed as the first argument. If successful,
11466** set *ppChangeset to point to a buffer containing the changeset
11467** and *pnChangeset to the size of the changeset in bytes before returning
11468** SQLITE_OK. If an error occurs, set both *ppChangeset and *pnChangeset to
11469** zero and return an SQLite error code.
11470**
11471** A changeset consists of zero or more INSERT, UPDATE and/or DELETE changes,
11472** each representing a change to a single row of an attached table. An INSERT
11473** change contains the values of each field of a new database row. A DELETE
11474** contains the original values of each field of a deleted database row. An
11475** UPDATE change contains the original values of each field of an updated
11476** database row along with the updated values for each updated non-primary-key
11477** column. It is not possible for an UPDATE change to represent a change that
11478** modifies the values of primary key columns. If such a change is made, it
11479** is represented in a changeset as a DELETE followed by an INSERT.
11480**
11481** Changes are not recorded for rows that have NULL values stored in one or
11482** more of their PRIMARY KEY columns. If such a row is inserted or deleted,
11483** no corresponding change is present in the changesets returned by this
11484** function. If an existing row with one or more NULL values stored in
11485** PRIMARY KEY columns is updated so that all PRIMARY KEY columns are non-NULL,
11486** only an INSERT is appears in the changeset. Similarly, if an existing row
11487** with non-NULL PRIMARY KEY values is updated so that one or more of its
11488** PRIMARY KEY columns are set to NULL, the resulting changeset contains a
11489** DELETE change only.
11490**
11491** The contents of a changeset may be traversed using an iterator created
11492** using the [sqlite3changeset_start()] API. A changeset may be applied to
11493** a database with a compatible schema using the [sqlite3changeset_apply()]
11494** API.
11495**
11496** Within a changeset generated by this function, all changes related to a
11497** single table are grouped together. In other words, when iterating through
11498** a changeset or when applying a changeset to a database, all changes related
11499** to a single table are processed before moving on to the next table. Tables
11500** are sorted in the same order in which they were attached (or auto-attached)
11501** to the sqlite3_session object. The order in which the changes related to
11502** a single table are stored is undefined.
11503**
11504** Following a successful call to this function, it is the responsibility of
11505** the caller to eventually free the buffer that *ppChangeset points to using
11506** [sqlite3_free()].
11507**
11508** <h3>Changeset Generation</h3>
11509**
11510** Once a table has been attached to a session object, the session object
11511** records the primary key values of all new rows inserted into the table.
11512** It also records the original primary key and other column values of any
11513** deleted or updated rows. For each unique primary key value, data is only
11514** recorded once - the first time a row with said primary key is inserted,
11515** updated or deleted in the lifetime of the session.
11516**
11517** There is one exception to the previous paragraph: when a row is inserted,
11518** updated or deleted, if one or more of its primary key columns contain a
11519** NULL value, no record of the change is made.
11520**
11521** The session object therefore accumulates two types of records - those
11522** that consist of primary key values only (created when the user inserts
11523** a new record) and those that consist of the primary key values and the
11524** original values of other table columns (created when the users deletes
11525** or updates a record).
11526**
11527** When this function is called, the requested changeset is created using
11528** both the accumulated records and the current contents of the database
11529** file. Specifically:
11530**
11531** <ul>
11532** <li> For each record generated by an insert, the database is queried
11533** for a row with a matching primary key. If one is found, an INSERT
11534** change is added to the changeset. If no such row is found, no change
11535** is added to the changeset.
11536**
11537** <li> For each record generated by an update or delete, the database is
11538** queried for a row with a matching primary key. If such a row is
11539** found and one or more of the non-primary key fields have been
11540** modified from their original values, an UPDATE change is added to
11541** the changeset. Or, if no such row is found in the table, a DELETE
11542** change is added to the changeset. If there is a row with a matching
11543** primary key in the database, but all fields contain their original
11544** values, no change is added to the changeset.
11545** </ul>
11546**
11547** This means, amongst other things, that if a row is inserted and then later
11548** deleted while a session object is active, neither the insert nor the delete
11549** will be present in the changeset. Or if a row is deleted and then later a
11550** row with the same primary key values inserted while a session object is
11551** active, the resulting changeset will contain an UPDATE change instead of
11552** a DELETE and an INSERT.
11553**
11554** When a session object is disabled (see the [sqlite3session_enable()] API),
11555** it does not accumulate records when rows are inserted, updated or deleted.
11556** This may appear to have some counter-intuitive effects if a single row
11557** is written to more than once during a session. For example, if a row
11558** is inserted while a session object is enabled, then later deleted while
11559** the same session object is disabled, no INSERT record will appear in the
11560** changeset, even though the delete took place while the session was disabled.
11561** Or, if one field of a row is updated while a session is enabled, and
11562** then another field of the same row is updated while the session is disabled,
11563** the resulting changeset will contain an UPDATE change that updates both
11564** fields.
11565*/
11566SQLITE_API int sqlite3session_changeset(
11567 sqlite3_session *pSession, /* Session object */
11568 int *pnChangeset, /* OUT: Size of buffer at *ppChangeset */
11569 void **ppChangeset /* OUT: Buffer containing changeset */
11570);
11571
11572/*
11573** CAPI3REF: Return An Upper-limit For The Size Of The Changeset
11574** METHOD: sqlite3_session
11575**
11576** By default, this function always returns 0. For it to return
11577** a useful result, the sqlite3_session object must have been configured
11578** to enable this API using sqlite3session_object_config() with the
11579** SQLITE_SESSION_OBJCONFIG_SIZE verb.
11580**
11581** When enabled, this function returns an upper limit, in bytes, for the size
11582** of the changeset that might be produced if sqlite3session_changeset() were
11583** called. The final changeset size might be equal to or smaller than the
11584** size in bytes returned by this function.
11585*/
11586SQLITE_API sqlite3_int64 sqlite3session_changeset_size(sqlite3_session *pSession);
11587
11588/*
11589** CAPI3REF: Load The Difference Between Tables Into A Session
11590** METHOD: sqlite3_session
11591**
11592** If it is not already attached to the session object passed as the first
11593** argument, this function attaches table zTbl in the same manner as the
11594** [sqlite3session_attach()] function. If zTbl does not exist, or if it
11595** does not have a primary key, this function is a no-op (but does not return
11596** an error).
11597**
11598** Argument zFromDb must be the name of a database ("main", "temp" etc.)
11599** attached to the same database handle as the session object that contains
11600** a table compatible with the table attached to the session by this function.
11601** A table is considered compatible if it:
11602**
11603** <ul>
11604** <li> Has the same name,
11605** <li> Has the same set of columns declared in the same order, and
11606** <li> Has the same PRIMARY KEY definition.
11607** </ul>
11608**
11609** If the tables are not compatible, SQLITE_SCHEMA is returned. If the tables
11610** are compatible but do not have any PRIMARY KEY columns, it is not an error
11611** but no changes are added to the session object. As with other session
11612** APIs, tables without PRIMARY KEYs are simply ignored.
11613**
11614** This function adds a set of changes to the session object that could be
11615** used to update the table in database zFrom (call this the "from-table")
11616** so that its content is the same as the table attached to the session
11617** object (call this the "to-table"). Specifically:
11618**
11619** <ul>
11620** <li> For each row (primary key) that exists in the to-table but not in
11621** the from-table, an INSERT record is added to the session object.
11622**
11623** <li> For each row (primary key) that exists in the to-table but not in
11624** the from-table, a DELETE record is added to the session object.
11625**
11626** <li> For each row (primary key) that exists in both tables, but features
11627** different non-PK values in each, an UPDATE record is added to the
11628** session.
11629** </ul>
11630**
11631** To clarify, if this function is called and then a changeset constructed
11632** using [sqlite3session_changeset()], then after applying that changeset to
11633** database zFrom the contents of the two compatible tables would be
11634** identical.
11635**
11636** Unless the call to this function is a no-op as described above, it is an
11637** error if database zFrom does not exist or does not contain the required
11638** compatible table.
11639**
11640** If the operation is successful, SQLITE_OK is returned. Otherwise, an SQLite
11641** error code. In this case, if argument pzErrMsg is not NULL, *pzErrMsg
11642** may be set to point to a buffer containing an English language error
11643** message. It is the responsibility of the caller to free this buffer using
11644** sqlite3_free().
11645*/
11646SQLITE_API int sqlite3session_diff(
11647 sqlite3_session *pSession,
11648 const char *zFromDb,
11649 const char *zTbl,
11650 char **pzErrMsg
11651);
11652
11653
11654/*
11655** CAPI3REF: Generate A Patchset From A Session Object
11656** METHOD: sqlite3_session
11657**
11658** The differences between a patchset and a changeset are that:
11659**
11660** <ul>
11661** <li> DELETE records consist of the primary key fields only. The
11662** original values of other fields are omitted.
11663** <li> The original values of any modified fields are omitted from
11664** UPDATE records.
11665** </ul>
11666**
11667** A patchset blob may be used with up to date versions of all
11668** sqlite3changeset_xxx API functions except for sqlite3changeset_invert(),
11669** which returns SQLITE_CORRUPT if it is passed a patchset. Similarly,
11670** attempting to use a patchset blob with old versions of the
11671** sqlite3changeset_xxx APIs also provokes an SQLITE_CORRUPT error.
11672**
11673** Because the non-primary key "old.*" fields are omitted, no
11674** SQLITE_CHANGESET_DATA conflicts can be detected or reported if a patchset
11675** is passed to the sqlite3changeset_apply() API. Other conflict types work
11676** in the same way as for changesets.
11677**
11678** Changes within a patchset are ordered in the same way as for changesets
11679** generated by the sqlite3session_changeset() function (i.e. all changes for
11680** a single table are grouped together, tables appear in the order in which
11681** they were attached to the session object).
11682*/
11683SQLITE_API int sqlite3session_patchset(
11684 sqlite3_session *pSession, /* Session object */
11685 int *pnPatchset, /* OUT: Size of buffer at *ppPatchset */
11686 void **ppPatchset /* OUT: Buffer containing patchset */
11687);
11688
11689/*
11690** CAPI3REF: Test if a changeset has recorded any changes.
11691**
11692** Return non-zero if no changes to attached tables have been recorded by
11693** the session object passed as the first argument. Otherwise, if one or
11694** more changes have been recorded, return zero.
11695**
11696** Even if this function returns zero, it is possible that calling
11697** [sqlite3session_changeset()] on the session handle may still return a
11698** changeset that contains no changes. This can happen when a row in
11699** an attached table is modified and then later on the original values
11700** are restored. However, if this function returns non-zero, then it is
11701** guaranteed that a call to sqlite3session_changeset() will return a
11702** changeset containing zero changes.
11703*/
11704SQLITE_API int sqlite3session_isempty(sqlite3_session *pSession);
11705
11706/*
11707** CAPI3REF: Query for the amount of heap memory used by a session object.
11708**
11709** This API returns the total amount of heap memory in bytes currently
11710** used by the session object passed as the only argument.
11711*/
11712SQLITE_API sqlite3_int64 sqlite3session_memory_used(sqlite3_session *pSession);
11713
11714/*
11715** CAPI3REF: Create An Iterator To Traverse A Changeset
11716** CONSTRUCTOR: sqlite3_changeset_iter
11717**
11718** Create an iterator used to iterate through the contents of a changeset.
11719** If successful, *pp is set to point to the iterator handle and SQLITE_OK
11720** is returned. Otherwise, if an error occurs, *pp is set to zero and an
11721** SQLite error code is returned.
11722**
11723** The following functions can be used to advance and query a changeset
11724** iterator created by this function:
11725**
11726** <ul>
11727** <li> [sqlite3changeset_next()]
11728** <li> [sqlite3changeset_op()]
11729** <li> [sqlite3changeset_new()]
11730** <li> [sqlite3changeset_old()]
11731** </ul>
11732**
11733** It is the responsibility of the caller to eventually destroy the iterator
11734** by passing it to [sqlite3changeset_finalize()]. The buffer containing the
11735** changeset (pChangeset) must remain valid until after the iterator is
11736** destroyed.
11737**
11738** Assuming the changeset blob was created by one of the
11739** [sqlite3session_changeset()], [sqlite3changeset_concat()] or
11740** [sqlite3changeset_invert()] functions, all changes within the changeset
11741** that apply to a single table are grouped together. This means that when
11742** an application iterates through a changeset using an iterator created by
11743** this function, all changes that relate to a single table are visited
11744** consecutively. There is no chance that the iterator will visit a change
11745** the applies to table X, then one for table Y, and then later on visit
11746** another change for table X.
11747**
11748** The behavior of sqlite3changeset_start_v2() and its streaming equivalent
11749** may be modified by passing a combination of
11750** [SQLITE_CHANGESETSTART_INVERT | supported flags] as the 4th parameter.
11751**
11752** Note that the sqlite3changeset_start_v2() API is still <b>experimental</b>
11753** and therefore subject to change.
11754*/
11755SQLITE_API int sqlite3changeset_start(
11756 sqlite3_changeset_iter **pp, /* OUT: New changeset iterator handle */
11757 int nChangeset, /* Size of changeset blob in bytes */
11758 void *pChangeset /* Pointer to blob containing changeset */
11759);
11760SQLITE_API int sqlite3changeset_start_v2(
11761 sqlite3_changeset_iter **pp, /* OUT: New changeset iterator handle */
11762 int nChangeset, /* Size of changeset blob in bytes */
11763 void *pChangeset, /* Pointer to blob containing changeset */
11764 int flags /* SESSION_CHANGESETSTART_* flags */
11765);
11766
11767/*
11768** CAPI3REF: Flags for sqlite3changeset_start_v2
11769**
11770** The following flags may passed via the 4th parameter to
11771** [sqlite3changeset_start_v2] and [sqlite3changeset_start_v2_strm]:
11772**
11773** <dt>SQLITE_CHANGESETSTART_INVERT <dd>
11774** Invert the changeset while iterating through it. This is equivalent to
11775** inverting a changeset using sqlite3changeset_invert() before applying it.
11776** It is an error to specify this flag with a patchset.
11777*/
11778#define SQLITE_CHANGESETSTART_INVERT 0x0002
11779
11780
11781/*
11782** CAPI3REF: Advance A Changeset Iterator
11783** METHOD: sqlite3_changeset_iter
11784**
11785** This function may only be used with iterators created by the function
11786** [sqlite3changeset_start()]. If it is called on an iterator passed to
11787** a conflict-handler callback by [sqlite3changeset_apply()], SQLITE_MISUSE
11788** is returned and the call has no effect.
11789**
11790** Immediately after an iterator is created by sqlite3changeset_start(), it
11791** does not point to any change in the changeset. Assuming the changeset
11792** is not empty, the first call to this function advances the iterator to
11793** point to the first change in the changeset. Each subsequent call advances
11794** the iterator to point to the next change in the changeset (if any). If
11795** no error occurs and the iterator points to a valid change after a call
11796** to sqlite3changeset_next() has advanced it, SQLITE_ROW is returned.
11797** Otherwise, if all changes in the changeset have already been visited,
11798** SQLITE_DONE is returned.
11799**
11800** If an error occurs, an SQLite error code is returned. Possible error
11801** codes include SQLITE_CORRUPT (if the changeset buffer is corrupt) or
11802** SQLITE_NOMEM.
11803*/
11804SQLITE_API int sqlite3changeset_next(sqlite3_changeset_iter *pIter);
11805
11806/*
11807** CAPI3REF: Obtain The Current Operation From A Changeset Iterator
11808** METHOD: sqlite3_changeset_iter
11809**
11810** The pIter argument passed to this function may either be an iterator
11811** passed to a conflict-handler by [sqlite3changeset_apply()], or an iterator
11812** created by [sqlite3changeset_start()]. In the latter case, the most recent
11813** call to [sqlite3changeset_next()] must have returned [SQLITE_ROW]. If this
11814** is not the case, this function returns [SQLITE_MISUSE].
11815**
11816** Arguments pOp, pnCol and pzTab may not be NULL. Upon return, three
11817** outputs are set through these pointers:
11818**
11819** *pOp is set to one of [SQLITE_INSERT], [SQLITE_DELETE] or [SQLITE_UPDATE],
11820** depending on the type of change that the iterator currently points to;
11821**
11822** *pnCol is set to the number of columns in the table affected by the change; and
11823**
11824** *pzTab is set to point to a nul-terminated utf-8 encoded string containing
11825** the name of the table affected by the current change. The buffer remains
11826** valid until either sqlite3changeset_next() is called on the iterator
11827** or until the conflict-handler function returns.
11828**
11829** If pbIndirect is not NULL, then *pbIndirect is set to true (1) if the change
11830** is an indirect change, or false (0) otherwise. See the documentation for
11831** [sqlite3session_indirect()] for a description of direct and indirect
11832** changes.
11833**
11834** If no error occurs, SQLITE_OK is returned. If an error does occur, an
11835** SQLite error code is returned. The values of the output variables may not
11836** be trusted in this case.
11837*/
11838SQLITE_API int sqlite3changeset_op(
11839 sqlite3_changeset_iter *pIter, /* Iterator object */
11840 const char **pzTab, /* OUT: Pointer to table name */
11841 int *pnCol, /* OUT: Number of columns in table */
11842 int *pOp, /* OUT: SQLITE_INSERT, DELETE or UPDATE */
11843 int *pbIndirect /* OUT: True for an 'indirect' change */
11844);
11845
11846/*
11847** CAPI3REF: Obtain The Primary Key Definition Of A Table
11848** METHOD: sqlite3_changeset_iter
11849**
11850** For each modified table, a changeset includes the following:
11851**
11852** <ul>
11853** <li> The number of columns in the table, and
11854** <li> Which of those columns make up the tables PRIMARY KEY.
11855** </ul>
11856**
11857** This function is used to find which columns comprise the PRIMARY KEY of
11858** the table modified by the change that iterator pIter currently points to.
11859** If successful, *pabPK is set to point to an array of nCol entries, where
11860** nCol is the number of columns in the table. Elements of *pabPK are set to
11861** 0x01 if the corresponding column is part of the tables primary key, or
11862** 0x00 if it is not.
11863**
11864** If argument pnCol is not NULL, then *pnCol is set to the number of columns
11865** in the table.
11866**
11867** If this function is called when the iterator does not point to a valid
11868** entry, SQLITE_MISUSE is returned and the output variables zeroed. Otherwise,
11869** SQLITE_OK is returned and the output variables populated as described
11870** above.
11871*/
11872SQLITE_API int sqlite3changeset_pk(
11873 sqlite3_changeset_iter *pIter, /* Iterator object */
11874 unsigned char **pabPK, /* OUT: Array of boolean - true for PK cols */
11875 int *pnCol /* OUT: Number of entries in output array */
11876);
11877
11878/*
11879** CAPI3REF: Obtain old.* Values From A Changeset Iterator
11880** METHOD: sqlite3_changeset_iter
11881**
11882** The pIter argument passed to this function may either be an iterator
11883** passed to a conflict-handler by [sqlite3changeset_apply()], or an iterator
11884** created by [sqlite3changeset_start()]. In the latter case, the most recent
11885** call to [sqlite3changeset_next()] must have returned SQLITE_ROW.
11886** Furthermore, it may only be called if the type of change that the iterator
11887** currently points to is either [SQLITE_DELETE] or [SQLITE_UPDATE]. Otherwise,
11888** this function returns [SQLITE_MISUSE] and sets *ppValue to NULL.
11889**
11890** Argument iVal must be greater than or equal to 0, and less than the number
11891** of columns in the table affected by the current change. Otherwise,
11892** [SQLITE_RANGE] is returned and *ppValue is set to NULL.
11893**
11894** If successful, this function sets *ppValue to point to a protected
11895** sqlite3_value object containing the iVal'th value from the vector of
11896** original row values stored as part of the UPDATE or DELETE change and
11897** returns SQLITE_OK. The name of the function comes from the fact that this
11898** is similar to the "old.*" columns available to update or delete triggers.
11899**
11900** If some other error occurs (e.g. an OOM condition), an SQLite error code
11901** is returned and *ppValue is set to NULL.
11902*/
11903SQLITE_API int sqlite3changeset_old(
11904 sqlite3_changeset_iter *pIter, /* Changeset iterator */
11905 int iVal, /* Column number */
11906 sqlite3_value **ppValue /* OUT: Old value (or NULL pointer) */
11907);
11908
11909/*
11910** CAPI3REF: Obtain new.* Values From A Changeset Iterator
11911** METHOD: sqlite3_changeset_iter
11912**
11913** The pIter argument passed to this function may either be an iterator
11914** passed to a conflict-handler by [sqlite3changeset_apply()], or an iterator
11915** created by [sqlite3changeset_start()]. In the latter case, the most recent
11916** call to [sqlite3changeset_next()] must have returned SQLITE_ROW.
11917** Furthermore, it may only be called if the type of change that the iterator
11918** currently points to is either [SQLITE_UPDATE] or [SQLITE_INSERT]. Otherwise,
11919** this function returns [SQLITE_MISUSE] and sets *ppValue to NULL.
11920**
11921** Argument iVal must be greater than or equal to 0, and less than the number
11922** of columns in the table affected by the current change. Otherwise,
11923** [SQLITE_RANGE] is returned and *ppValue is set to NULL.
11924**
11925** If successful, this function sets *ppValue to point to a protected
11926** sqlite3_value object containing the iVal'th value from the vector of
11927** new row values stored as part of the UPDATE or INSERT change and
11928** returns SQLITE_OK. If the change is an UPDATE and does not include
11929** a new value for the requested column, *ppValue is set to NULL and
11930** SQLITE_OK returned. The name of the function comes from the fact that
11931** this is similar to the "new.*" columns available to update or delete
11932** triggers.
11933**
11934** If some other error occurs (e.g. an OOM condition), an SQLite error code
11935** is returned and *ppValue is set to NULL.
11936*/
11937SQLITE_API int sqlite3changeset_new(
11938 sqlite3_changeset_iter *pIter, /* Changeset iterator */
11939 int iVal, /* Column number */
11940 sqlite3_value **ppValue /* OUT: New value (or NULL pointer) */
11941);
11942
11943/*
11944** CAPI3REF: Obtain Conflicting Row Values From A Changeset Iterator
11945** METHOD: sqlite3_changeset_iter
11946**
11947** This function should only be used with iterator objects passed to a
11948** conflict-handler callback by [sqlite3changeset_apply()] with either
11949** [SQLITE_CHANGESET_DATA] or [SQLITE_CHANGESET_CONFLICT]. If this function
11950** is called on any other iterator, [SQLITE_MISUSE] is returned and *ppValue
11951** is set to NULL.
11952**
11953** Argument iVal must be greater than or equal to 0, and less than the number
11954** of columns in the table affected by the current change. Otherwise,
11955** [SQLITE_RANGE] is returned and *ppValue is set to NULL.
11956**
11957** If successful, this function sets *ppValue to point to a protected
11958** sqlite3_value object containing the iVal'th value from the
11959** "conflicting row" associated with the current conflict-handler callback
11960** and returns SQLITE_OK.
11961**
11962** If some other error occurs (e.g. an OOM condition), an SQLite error code
11963** is returned and *ppValue is set to NULL.
11964*/
11965SQLITE_API int sqlite3changeset_conflict(
11966 sqlite3_changeset_iter *pIter, /* Changeset iterator */
11967 int iVal, /* Column number */
11968 sqlite3_value **ppValue /* OUT: Value from conflicting row */
11969);
11970
11971/*
11972** CAPI3REF: Determine The Number Of Foreign Key Constraint Violations
11973** METHOD: sqlite3_changeset_iter
11974**
11975** This function may only be called with an iterator passed to an
11976** SQLITE_CHANGESET_FOREIGN_KEY conflict handler callback. In this case
11977** it sets the output variable to the total number of known foreign key
11978** violations in the destination database and returns SQLITE_OK.
11979**
11980** In all other cases this function returns SQLITE_MISUSE.
11981*/
11982SQLITE_API int sqlite3changeset_fk_conflicts(
11983 sqlite3_changeset_iter *pIter, /* Changeset iterator */
11984 int *pnOut /* OUT: Number of FK violations */
11985);
11986
11987
11988/*
11989** CAPI3REF: Finalize A Changeset Iterator
11990** METHOD: sqlite3_changeset_iter
11991**
11992** This function is used to finalize an iterator allocated with
11993** [sqlite3changeset_start()].
11994**
11995** This function should only be called on iterators created using the
11996** [sqlite3changeset_start()] function. If an application calls this
11997** function with an iterator passed to a conflict-handler by
11998** [sqlite3changeset_apply()], [SQLITE_MISUSE] is immediately returned and the
11999** call has no effect.
12000**
12001** If an error was encountered within a call to an sqlite3changeset_xxx()
12002** function (for example an [SQLITE_CORRUPT] in [sqlite3changeset_next()] or an
12003** [SQLITE_NOMEM] in [sqlite3changeset_new()]) then an error code corresponding
12004** to that error is returned by this function. Otherwise, SQLITE_OK is
12005** returned. This is to allow the following pattern (pseudo-code):
12006**
12007** <pre>
12008** sqlite3changeset_start();
12009** while( SQLITE_ROW==sqlite3changeset_next() ){
12010** // Do something with change.
12011** }
12012** rc = sqlite3changeset_finalize();
12013** if( rc!=SQLITE_OK ){
12014** // An error has occurred
12015** }
12016** </pre>
12017*/
12018SQLITE_API int sqlite3changeset_finalize(sqlite3_changeset_iter *pIter);
12019
12020/*
12021** CAPI3REF: Invert A Changeset
12022**
12023** This function is used to "invert" a changeset object. Applying an inverted
12024** changeset to a database reverses the effects of applying the uninverted
12025** changeset. Specifically:
12026**
12027** <ul>
12028** <li> Each DELETE change is changed to an INSERT, and
12029** <li> Each INSERT change is changed to a DELETE, and
12030** <li> For each UPDATE change, the old.* and new.* values are exchanged.
12031** </ul>
12032**
12033** This function does not change the order in which changes appear within
12034** the changeset. It merely reverses the sense of each individual change.
12035**
12036** If successful, a pointer to a buffer containing the inverted changeset
12037** is stored in *ppOut, the size of the same buffer is stored in *pnOut, and
12038** SQLITE_OK is returned. If an error occurs, both *pnOut and *ppOut are
12039** zeroed and an SQLite error code returned.
12040**
12041** It is the responsibility of the caller to eventually call sqlite3_free()
12042** on the *ppOut pointer to free the buffer allocation following a successful
12043** call to this function.
12044**
12045** WARNING/TODO: This function currently assumes that the input is a valid
12046** changeset. If it is not, the results are undefined.
12047*/
12048SQLITE_API int sqlite3changeset_invert(
12049 int nIn, const void *pIn, /* Input changeset */
12050 int *pnOut, void **ppOut /* OUT: Inverse of input */
12051);
12052
12053/*
12054** CAPI3REF: Concatenate Two Changeset Objects
12055**
12056** This function is used to concatenate two changesets, A and B, into a
12057** single changeset. The result is a changeset equivalent to applying
12058** changeset A followed by changeset B.
12059**
12060** This function combines the two input changesets using an
12061** sqlite3_changegroup object. Calling it produces similar results as the
12062** following code fragment:
12063**
12064** <pre>
12065** sqlite3_changegroup *pGrp;
12066** rc = sqlite3_changegroup_new(&pGrp);
12067** if( rc==SQLITE_OK ) rc = sqlite3changegroup_add(pGrp, nA, pA);
12068** if( rc==SQLITE_OK ) rc = sqlite3changegroup_add(pGrp, nB, pB);
12069** if( rc==SQLITE_OK ){
12070** rc = sqlite3changegroup_output(pGrp, pnOut, ppOut);
12071** }else{
12072** *ppOut = 0;
12073** *pnOut = 0;
12074** }
12075** </pre>
12076**
12077** Refer to the sqlite3_changegroup documentation below for details.
12078*/
12079SQLITE_API int sqlite3changeset_concat(
12080 int nA, /* Number of bytes in buffer pA */
12081 void *pA, /* Pointer to buffer containing changeset A */
12082 int nB, /* Number of bytes in buffer pB */
12083 void *pB, /* Pointer to buffer containing changeset B */
12084 int *pnOut, /* OUT: Number of bytes in output changeset */
12085 void **ppOut /* OUT: Buffer containing output changeset */
12086);
12087
12088/*
12089** CAPI3REF: Changegroup Handle
12090**
12091** A changegroup is an object used to combine two or more
12092** [changesets] or [patchsets]
12093*/
12094typedef struct sqlite3_changegroup sqlite3_changegroup;
12095
12096/*
12097** CAPI3REF: Create A New Changegroup Object
12098** CONSTRUCTOR: sqlite3_changegroup
12099**
12100** An sqlite3_changegroup object is used to combine two or more changesets
12101** (or patchsets) into a single changeset (or patchset). A single changegroup
12102** object may combine changesets or patchsets, but not both. The output is
12103** always in the same format as the input.
12104**
12105** If successful, this function returns SQLITE_OK and populates (*pp) with
12106** a pointer to a new sqlite3_changegroup object before returning. The caller
12107** should eventually free the returned object using a call to
12108** sqlite3changegroup_delete(). If an error occurs, an SQLite error code
12109** (i.e. SQLITE_NOMEM) is returned and *pp is set to NULL.
12110**
12111** The usual usage pattern for an sqlite3_changegroup object is as follows:
12112**
12113** <ul>
12114** <li> It is created using a call to sqlite3changegroup_new().
12115**
12116** <li> Zero or more changesets (or patchsets) are added to the object
12117** by calling sqlite3changegroup_add().
12118**
12119** <li> The result of combining all input changesets together is obtained
12120** by the application via a call to sqlite3changegroup_output().
12121**
12122** <li> The object is deleted using a call to sqlite3changegroup_delete().
12123** </ul>
12124**
12125** Any number of calls to add() and output() may be made between the calls to
12126** new() and delete(), and in any order.
12127**
12128** As well as the regular sqlite3changegroup_add() and
12129** sqlite3changegroup_output() functions, also available are the streaming
12130** versions sqlite3changegroup_add_strm() and sqlite3changegroup_output_strm().
12131*/
12132SQLITE_API int sqlite3changegroup_new(sqlite3_changegroup **pp);
12133
12134/*
12135** CAPI3REF: Add a Schema to a Changegroup
12136** METHOD: sqlite3_changegroup_schema
12137**
12138** This method may be used to optionally enforce the rule that the changesets
12139** added to the changegroup handle must match the schema of database zDb
12140** ("main", "temp", or the name of an attached database). If
12141** sqlite3changegroup_add() is called to add a changeset that is not compatible
12142** with the configured schema, SQLITE_SCHEMA is returned and the changegroup
12143** object is left in an undefined state.
12144**
12145** A changeset schema is considered compatible with the database schema in
12146** the same way as for sqlite3changeset_apply(). Specifically, for each
12147** table in the changeset, there exists a database table with:
12148**
12149** <ul>
12150** <li> The name identified by the changeset, and
12151** <li> at least as many columns as recorded in the changeset, and
12152** <li> the primary key columns in the same position as recorded in
12153** the changeset.
12154** </ul>
12155**
12156** The output of the changegroup object always has the same schema as the
12157** database nominated using this function. In cases where changesets passed
12158** to sqlite3changegroup_add() have fewer columns than the corresponding table
12159** in the database schema, these are filled in using the default column
12160** values from the database schema. This makes it possible to combined
12161** changesets that have different numbers of columns for a single table
12162** within a changegroup, provided that they are otherwise compatible.
12163*/
12164SQLITE_API int sqlite3changegroup_schema(sqlite3_changegroup*, sqlite3*, const char *zDb);
12165
12166/*
12167** CAPI3REF: Add A Changeset To A Changegroup
12168** METHOD: sqlite3_changegroup
12169**
12170** Add all changes within the changeset (or patchset) in buffer pData (size
12171** nData bytes) to the changegroup.
12172**
12173** If the buffer contains a patchset, then all prior calls to this function
12174** on the same changegroup object must also have specified patchsets. Or, if
12175** the buffer contains a changeset, so must have the earlier calls to this
12176** function. Otherwise, SQLITE_ERROR is returned and no changes are added
12177** to the changegroup.
12178**
12179** Rows within the changeset and changegroup are identified by the values in
12180** their PRIMARY KEY columns. A change in the changeset is considered to
12181** apply to the same row as a change already present in the changegroup if
12182** the two rows have the same primary key.
12183**
12184** Changes to rows that do not already appear in the changegroup are
12185** simply copied into it. Or, if both the new changeset and the changegroup
12186** contain changes that apply to a single row, the final contents of the
12187** changegroup depends on the type of each change, as follows:
12188**
12189** <table border=1 style="margin-left:8ex;margin-right:8ex">
12190** <tr><th style="white-space:pre">Existing Change </th>
12191** <th style="white-space:pre">New Change </th>
12192** <th>Output Change
12193** <tr><td>INSERT <td>INSERT <td>
12194** The new change is ignored. This case does not occur if the new
12195** changeset was recorded immediately after the changesets already
12196** added to the changegroup.
12197** <tr><td>INSERT <td>UPDATE <td>
12198** The INSERT change remains in the changegroup. The values in the
12199** INSERT change are modified as if the row was inserted by the
12200** existing change and then updated according to the new change.
12201** <tr><td>INSERT <td>DELETE <td>
12202** The existing INSERT is removed from the changegroup. The DELETE is
12203** not added.
12204** <tr><td>UPDATE <td>INSERT <td>
12205** The new change is ignored. This case does not occur if the new
12206** changeset was recorded immediately after the changesets already
12207** added to the changegroup.
12208** <tr><td>UPDATE <td>UPDATE <td>
12209** The existing UPDATE remains within the changegroup. It is amended
12210** so that the accompanying values are as if the row was updated once
12211** by the existing change and then again by the new change.
12212** <tr><td>UPDATE <td>DELETE <td>
12213** The existing UPDATE is replaced by the new DELETE within the
12214** changegroup.
12215** <tr><td>DELETE <td>INSERT <td>
12216** If one or more of the column values in the row inserted by the
12217** new change differ from those in the row deleted by the existing
12218** change, the existing DELETE is replaced by an UPDATE within the
12219** changegroup. Otherwise, if the inserted row is exactly the same
12220** as the deleted row, the existing DELETE is simply discarded.
12221** <tr><td>DELETE <td>UPDATE <td>
12222** The new change is ignored. This case does not occur if the new
12223** changeset was recorded immediately after the changesets already
12224** added to the changegroup.
12225** <tr><td>DELETE <td>DELETE <td>
12226** The new change is ignored. This case does not occur if the new
12227** changeset was recorded immediately after the changesets already
12228** added to the changegroup.
12229** </table>
12230**
12231** If the new changeset contains changes to a table that is already present
12232** in the changegroup, then the number of columns and the position of the
12233** primary key columns for the table must be consistent. If this is not the
12234** case, this function fails with SQLITE_SCHEMA. Except, if the changegroup
12235** object has been configured with a database schema using the
12236** sqlite3changegroup_schema() API, then it is possible to combine changesets
12237** with different numbers of columns for a single table, provided that
12238** they are otherwise compatible.
12239**
12240** If the input changeset appears to be corrupt and the corruption is
12241** detected, SQLITE_CORRUPT is returned. Or, if an out-of-memory condition
12242** occurs during processing, this function returns SQLITE_NOMEM.
12243**
12244** In all cases, if an error occurs the state of the final contents of the
12245** changegroup is undefined. If no error occurs, SQLITE_OK is returned.
12246*/
12247SQLITE_API int sqlite3changegroup_add(sqlite3_changegroup*, int nData, void *pData);
12248
12249/*
12250** CAPI3REF: Add A Single Change To A Changegroup
12251** METHOD: sqlite3_changegroup
12252**
12253** This function adds the single change currently indicated by the iterator
12254** passed as the second argument to the changegroup object. The rules for
12255** adding the change are just as described for [sqlite3changegroup_add()].
12256**
12257** If the change is successfully added to the changegroup, SQLITE_OK is
12258** returned. Otherwise, an SQLite error code is returned.
12259**
12260** The iterator must point to a valid entry when this function is called.
12261** If it does not, SQLITE_ERROR is returned and no change is added to the
12262** changegroup. Additionally, the iterator must not have been opened with
12263** the SQLITE_CHANGESETAPPLY_INVERT flag. In this case SQLITE_ERROR is also
12264** returned.
12265*/
12266SQLITE_API int sqlite3changegroup_add_change(
12267 sqlite3_changegroup*,
12268 sqlite3_changeset_iter*
12269);
12270
12271
12272
12273/*
12274** CAPI3REF: Obtain A Composite Changeset From A Changegroup
12275** METHOD: sqlite3_changegroup
12276**
12277** Obtain a buffer containing a changeset (or patchset) representing the
12278** current contents of the changegroup. If the inputs to the changegroup
12279** were themselves changesets, the output is a changeset. Or, if the
12280** inputs were patchsets, the output is also a patchset.
12281**
12282** As with the output of the sqlite3session_changeset() and
12283** sqlite3session_patchset() functions, all changes related to a single
12284** table are grouped together in the output of this function. Tables appear
12285** in the same order as for the very first changeset added to the changegroup.
12286** If the second or subsequent changesets added to the changegroup contain
12287** changes for tables that do not appear in the first changeset, they are
12288** appended onto the end of the output changeset, again in the order in
12289** which they are first encountered.
12290**
12291** If an error occurs, an SQLite error code is returned and the output
12292** variables (*pnData) and (*ppData) are set to 0. Otherwise, SQLITE_OK
12293** is returned and the output variables are set to the size of and a
12294** pointer to the output buffer, respectively. In this case it is the
12295** responsibility of the caller to eventually free the buffer using a
12296** call to sqlite3_free().
12297*/
12298SQLITE_API int sqlite3changegroup_output(
12299 sqlite3_changegroup*,
12300 int *pnData, /* OUT: Size of output buffer in bytes */
12301 void **ppData /* OUT: Pointer to output buffer */
12302);
12303
12304/*
12305** CAPI3REF: Delete A Changegroup Object
12306** DESTRUCTOR: sqlite3_changegroup
12307*/
12308SQLITE_API void sqlite3changegroup_delete(sqlite3_changegroup*);
12309
12310/*
12311** CAPI3REF: Apply A Changeset To A Database
12312**
12313** Apply a changeset or patchset to a database. These functions attempt to
12314** update the "main" database attached to handle db with the changes found in
12315** the changeset passed via the second and third arguments.
12316**
12317** The fourth argument (xFilter) passed to these functions is the "filter
12318** callback". If it is not NULL, then for each table affected by at least one
12319** change in the changeset, the filter callback is invoked with
12320** the table name as the second argument, and a copy of the context pointer
12321** passed as the sixth argument as the first. If the "filter callback"
12322** returns zero, then no attempt is made to apply any changes to the table.
12323** Otherwise, if the return value is non-zero or the xFilter argument to
12324** is NULL, all changes related to the table are attempted.
12325**
12326** For each table that is not excluded by the filter callback, this function
12327** tests that the target database contains a compatible table. A table is
12328** considered compatible if all of the following are true:
12329**
12330** <ul>
12331** <li> The table has the same name as the name recorded in the
12332** changeset, and
12333** <li> The table has at least as many columns as recorded in the
12334** changeset, and
12335** <li> The table has primary key columns in the same position as
12336** recorded in the changeset.
12337** </ul>
12338**
12339** If there is no compatible table, it is not an error, but none of the
12340** changes associated with the table are applied. A warning message is issued
12341** via the sqlite3_log() mechanism with the error code SQLITE_SCHEMA. At most
12342** one such warning is issued for each table in the changeset.
12343**
12344** For each change for which there is a compatible table, an attempt is made
12345** to modify the table contents according to the UPDATE, INSERT or DELETE
12346** change. If a change cannot be applied cleanly, the conflict handler
12347** function passed as the fifth argument to sqlite3changeset_apply() may be
12348** invoked. A description of exactly when the conflict handler is invoked for
12349** each type of change is below.
12350**
12351** Unlike the xFilter argument, xConflict may not be passed NULL. The results
12352** of passing anything other than a valid function pointer as the xConflict
12353** argument are undefined.
12354**
12355** Each time the conflict handler function is invoked, it must return one
12356** of [SQLITE_CHANGESET_OMIT], [SQLITE_CHANGESET_ABORT] or
12357** [SQLITE_CHANGESET_REPLACE]. SQLITE_CHANGESET_REPLACE may only be returned
12358** if the second argument passed to the conflict handler is either
12359** SQLITE_CHANGESET_DATA or SQLITE_CHANGESET_CONFLICT. If the conflict-handler
12360** returns an illegal value, any changes already made are rolled back and
12361** the call to sqlite3changeset_apply() returns SQLITE_MISUSE. Different
12362** actions are taken by sqlite3changeset_apply() depending on the value
12363** returned by each invocation of the conflict-handler function. Refer to
12364** the documentation for the three
12365** [SQLITE_CHANGESET_OMIT|available return values] for details.
12366**
12367** <dl>
12368** <dt>DELETE Changes<dd>
12369** For each DELETE change, the function checks if the target database
12370** contains a row with the same primary key value (or values) as the
12371** original row values stored in the changeset. If it does, and the values
12372** stored in all non-primary key columns also match the values stored in
12373** the changeset the row is deleted from the target database.
12374**
12375** If a row with matching primary key values is found, but one or more of
12376** the non-primary key fields contains a value different from the original
12377** row value stored in the changeset, the conflict-handler function is
12378** invoked with [SQLITE_CHANGESET_DATA] as the second argument. If the
12379** database table has more columns than are recorded in the changeset,
12380** only the values of those non-primary key fields are compared against
12381** the current database contents - any trailing database table columns
12382** are ignored.
12383**
12384** If no row with matching primary key values is found in the database,
12385** the conflict-handler function is invoked with [SQLITE_CHANGESET_NOTFOUND]
12386** passed as the second argument.
12387**
12388** If the DELETE operation is attempted, but SQLite returns SQLITE_CONSTRAINT
12389** (which can only happen if a foreign key constraint is violated), the
12390** conflict-handler function is invoked with [SQLITE_CHANGESET_CONSTRAINT]
12391** passed as the second argument. This includes the case where the DELETE
12392** operation is attempted because an earlier call to the conflict handler
12393** function returned [SQLITE_CHANGESET_REPLACE].
12394**
12395** <dt>INSERT Changes<dd>
12396** For each INSERT change, an attempt is made to insert the new row into
12397** the database. If the changeset row contains fewer fields than the
12398** database table, the trailing fields are populated with their default
12399** values.
12400**
12401** If the attempt to insert the row fails because the database already
12402** contains a row with the same primary key values, the conflict handler
12403** function is invoked with the second argument set to
12404** [SQLITE_CHANGESET_CONFLICT].
12405**
12406** If the attempt to insert the row fails because of some other constraint
12407** violation (e.g. NOT NULL or UNIQUE), the conflict handler function is
12408** invoked with the second argument set to [SQLITE_CHANGESET_CONSTRAINT].
12409** This includes the case where the INSERT operation is re-attempted because
12410** an earlier call to the conflict handler function returned
12411** [SQLITE_CHANGESET_REPLACE].
12412**
12413** <dt>UPDATE Changes<dd>
12414** For each UPDATE change, the function checks if the target database
12415** contains a row with the same primary key value (or values) as the
12416** original row values stored in the changeset. If it does, and the values
12417** stored in all modified non-primary key columns also match the values
12418** stored in the changeset the row is updated within the target database.
12419**
12420** If a row with matching primary key values is found, but one or more of
12421** the modified non-primary key fields contains a value different from an
12422** original row value stored in the changeset, the conflict-handler function
12423** is invoked with [SQLITE_CHANGESET_DATA] as the second argument. Since
12424** UPDATE changes only contain values for non-primary key fields that are
12425** to be modified, only those fields need to match the original values to
12426** avoid the SQLITE_CHANGESET_DATA conflict-handler callback.
12427**
12428** If no row with matching primary key values is found in the database,
12429** the conflict-handler function is invoked with [SQLITE_CHANGESET_NOTFOUND]
12430** passed as the second argument.
12431**
12432** If the UPDATE operation is attempted, but SQLite returns
12433** SQLITE_CONSTRAINT, the conflict-handler function is invoked with
12434** [SQLITE_CHANGESET_CONSTRAINT] passed as the second argument.
12435** This includes the case where the UPDATE operation is attempted after
12436** an earlier call to the conflict handler function returned
12437** [SQLITE_CHANGESET_REPLACE].
12438** </dl>
12439**
12440** It is safe to execute SQL statements, including those that write to the
12441** table that the callback related to, from within the xConflict callback.
12442** This can be used to further customize the application's conflict
12443** resolution strategy.
12444**
12445** All changes made by these functions are enclosed in a savepoint transaction.
12446** If any other error (aside from a constraint failure when attempting to
12447** write to the target database) occurs, then the savepoint transaction is
12448** rolled back, restoring the target database to its original state, and an
12449** SQLite error code returned.
12450**
12451** If the output parameters (ppRebase) and (pnRebase) are non-NULL and
12452** the input is a changeset (not a patchset), then sqlite3changeset_apply_v2()
12453** may set (*ppRebase) to point to a "rebase" that may be used with the
12454** sqlite3_rebaser APIs buffer before returning. In this case (*pnRebase)
12455** is set to the size of the buffer in bytes. It is the responsibility of the
12456** caller to eventually free any such buffer using sqlite3_free(). The buffer
12457** is only allocated and populated if one or more conflicts were encountered
12458** while applying the patchset. See comments surrounding the sqlite3_rebaser
12459** APIs for further details.
12460**
12461** The behavior of sqlite3changeset_apply_v2() and its streaming equivalent
12462** may be modified by passing a combination of
12463** [SQLITE_CHANGESETAPPLY_NOSAVEPOINT | supported flags] as the 9th parameter.
12464**
12465** Note that the sqlite3changeset_apply_v2() API is still <b>experimental</b>
12466** and therefore subject to change.
12467*/
12468SQLITE_API int sqlite3changeset_apply(
12469 sqlite3 *db, /* Apply change to "main" db of this handle */
12470 int nChangeset, /* Size of changeset in bytes */
12471 void *pChangeset, /* Changeset blob */
12472 int(*xFilter)(
12473 void *pCtx, /* Copy of sixth arg to _apply() */
12474 const char *zTab /* Table name */
12475 ),
12476 int(*xConflict)(
12477 void *pCtx, /* Copy of sixth arg to _apply() */
12478 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */
12479 sqlite3_changeset_iter *p /* Handle describing change and conflict */
12480 ),
12481 void *pCtx /* First argument passed to xConflict */
12482);
12483SQLITE_API int sqlite3changeset_apply_v2(
12484 sqlite3 *db, /* Apply change to "main" db of this handle */
12485 int nChangeset, /* Size of changeset in bytes */
12486 void *pChangeset, /* Changeset blob */
12487 int(*xFilter)(
12488 void *pCtx, /* Copy of sixth arg to _apply() */
12489 const char *zTab /* Table name */
12490 ),
12491 int(*xConflict)(
12492 void *pCtx, /* Copy of sixth arg to _apply() */
12493 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */
12494 sqlite3_changeset_iter *p /* Handle describing change and conflict */
12495 ),
12496 void *pCtx, /* First argument passed to xConflict */
12497 void **ppRebase, int *pnRebase, /* OUT: Rebase data */
12498 int flags /* SESSION_CHANGESETAPPLY_* flags */
12499);
12500
12501/*
12502** CAPI3REF: Flags for sqlite3changeset_apply_v2
12503**
12504** The following flags may passed via the 9th parameter to
12505** [sqlite3changeset_apply_v2] and [sqlite3changeset_apply_v2_strm]:
12506**
12507** <dl>
12508** <dt>SQLITE_CHANGESETAPPLY_NOSAVEPOINT <dd>
12509** Usually, the sessions module encloses all operations performed by
12510** a single call to apply_v2() or apply_v2_strm() in a [SAVEPOINT]. The
12511** SAVEPOINT is committed if the changeset or patchset is successfully
12512** applied, or rolled back if an error occurs. Specifying this flag
12513** causes the sessions module to omit this savepoint. In this case, if the
12514** caller has an open transaction or savepoint when apply_v2() is called,
12515** it may revert the partially applied changeset by rolling it back.
12516**
12517** <dt>SQLITE_CHANGESETAPPLY_INVERT <dd>
12518** Invert the changeset before applying it. This is equivalent to inverting
12519** a changeset using sqlite3changeset_invert() before applying it. It is
12520** an error to specify this flag with a patchset.
12521**
12522** <dt>SQLITE_CHANGESETAPPLY_IGNORENOOP <dd>
12523** Do not invoke the conflict handler callback for any changes that
12524** would not actually modify the database even if they were applied.
12525** Specifically, this means that the conflict handler is not invoked
12526** for:
12527** <ul>
12528** <li>a delete change if the row being deleted cannot be found,
12529** <li>an update change if the modified fields are already set to
12530** their new values in the conflicting row, or
12531** <li>an insert change if all fields of the conflicting row match
12532** the row being inserted.
12533** </ul>
12534**
12535** <dt>SQLITE_CHANGESETAPPLY_FKNOACTION <dd>
12536** If this flag it set, then all foreign key constraints in the target
12537** database behave as if they were declared with "ON UPDATE NO ACTION ON
12538** DELETE NO ACTION", even if they are actually CASCADE, RESTRICT, SET NULL
12539** or SET DEFAULT.
12540*/
12541#define SQLITE_CHANGESETAPPLY_NOSAVEPOINT 0x0001
12542#define SQLITE_CHANGESETAPPLY_INVERT 0x0002
12543#define SQLITE_CHANGESETAPPLY_IGNORENOOP 0x0004
12544#define SQLITE_CHANGESETAPPLY_FKNOACTION 0x0008
12545
12546/*
12547** CAPI3REF: Constants Passed To The Conflict Handler
12548**
12549** Values that may be passed as the second argument to a conflict-handler.
12550**
12551** <dl>
12552** <dt>SQLITE_CHANGESET_DATA<dd>
12553** The conflict handler is invoked with CHANGESET_DATA as the second argument
12554** when processing a DELETE or UPDATE change if a row with the required
12555** PRIMARY KEY fields is present in the database, but one or more other
12556** (non primary-key) fields modified by the update do not contain the
12557** expected "before" values.
12558**
12559** The conflicting row, in this case, is the database row with the matching
12560** primary key.
12561**
12562** <dt>SQLITE_CHANGESET_NOTFOUND<dd>
12563** The conflict handler is invoked with CHANGESET_NOTFOUND as the second
12564** argument when processing a DELETE or UPDATE change if a row with the
12565** required PRIMARY KEY fields is not present in the database.
12566**
12567** There is no conflicting row in this case. The results of invoking the
12568** sqlite3changeset_conflict() API are undefined.
12569**
12570** <dt>SQLITE_CHANGESET_CONFLICT<dd>
12571** CHANGESET_CONFLICT is passed as the second argument to the conflict
12572** handler while processing an INSERT change if the operation would result
12573** in duplicate primary key values.
12574**
12575** The conflicting row in this case is the database row with the matching
12576** primary key.
12577**
12578** <dt>SQLITE_CHANGESET_FOREIGN_KEY<dd>
12579** If foreign key handling is enabled, and applying a changeset leaves the
12580** database in a state containing foreign key violations, the conflict
12581** handler is invoked with CHANGESET_FOREIGN_KEY as the second argument
12582** exactly once before the changeset is committed. If the conflict handler
12583** returns CHANGESET_OMIT, the changes, including those that caused the
12584** foreign key constraint violation, are committed. Or, if it returns
12585** CHANGESET_ABORT, the changeset is rolled back.
12586**
12587** No current or conflicting row information is provided. The only function
12588** it is possible to call on the supplied sqlite3_changeset_iter handle
12589** is sqlite3changeset_fk_conflicts().
12590**
12591** <dt>SQLITE_CHANGESET_CONSTRAINT<dd>
12592** If any other constraint violation occurs while applying a change (i.e.
12593** a UNIQUE, CHECK or NOT NULL constraint), the conflict handler is
12594** invoked with CHANGESET_CONSTRAINT as the second argument.
12595**
12596** There is no conflicting row in this case. The results of invoking the
12597** sqlite3changeset_conflict() API are undefined.
12598**
12599** </dl>
12600*/
12601#define SQLITE_CHANGESET_DATA 1
12602#define SQLITE_CHANGESET_NOTFOUND 2
12603#define SQLITE_CHANGESET_CONFLICT 3
12604#define SQLITE_CHANGESET_CONSTRAINT 4
12605#define SQLITE_CHANGESET_FOREIGN_KEY 5
12606
12607/*
12608** CAPI3REF: Constants Returned By The Conflict Handler
12609**
12610** A conflict handler callback must return one of the following three values.
12611**
12612** <dl>
12613** <dt>SQLITE_CHANGESET_OMIT<dd>
12614** If a conflict handler returns this value no special action is taken. The
12615** change that caused the conflict is not applied. The session module
12616** continues to the next change in the changeset.
12617**
12618** <dt>SQLITE_CHANGESET_REPLACE<dd>
12619** This value may only be returned if the second argument to the conflict
12620** handler was SQLITE_CHANGESET_DATA or SQLITE_CHANGESET_CONFLICT. If this
12621** is not the case, any changes applied so far are rolled back and the
12622** call to sqlite3changeset_apply() returns SQLITE_MISUSE.
12623**
12624** If CHANGESET_REPLACE is returned by an SQLITE_CHANGESET_DATA conflict
12625** handler, then the conflicting row is either updated or deleted, depending
12626** on the type of change.
12627**
12628** If CHANGESET_REPLACE is returned by an SQLITE_CHANGESET_CONFLICT conflict
12629** handler, then the conflicting row is removed from the database and a
12630** second attempt to apply the change is made. If this second attempt fails,
12631** the original row is restored to the database before continuing.
12632**
12633** <dt>SQLITE_CHANGESET_ABORT<dd>
12634** If this value is returned, any changes applied so far are rolled back
12635** and the call to sqlite3changeset_apply() returns SQLITE_ABORT.
12636** </dl>
12637*/
12638#define SQLITE_CHANGESET_OMIT 0
12639#define SQLITE_CHANGESET_REPLACE 1
12640#define SQLITE_CHANGESET_ABORT 2
12641
12642/*
12643** CAPI3REF: Rebasing changesets
12644** EXPERIMENTAL
12645**
12646** Suppose there is a site hosting a database in state S0. And that
12647** modifications are made that move that database to state S1 and a
12648** changeset recorded (the "local" changeset). Then, a changeset based
12649** on S0 is received from another site (the "remote" changeset) and
12650** applied to the database. The database is then in state
12651** (S1+"remote"), where the exact state depends on any conflict
12652** resolution decisions (OMIT or REPLACE) made while applying "remote".
12653** Rebasing a changeset is to update it to take those conflict
12654** resolution decisions into account, so that the same conflicts
12655** do not have to be resolved elsewhere in the network.
12656**
12657** For example, if both the local and remote changesets contain an
12658** INSERT of the same key on "CREATE TABLE t1(a PRIMARY KEY, b)":
12659**
12660** local: INSERT INTO t1 VALUES(1, 'v1');
12661** remote: INSERT INTO t1 VALUES(1, 'v2');
12662**
12663** and the conflict resolution is REPLACE, then the INSERT change is
12664** removed from the local changeset (it was overridden). Or, if the
12665** conflict resolution was "OMIT", then the local changeset is modified
12666** to instead contain:
12667**
12668** UPDATE t1 SET b = 'v2' WHERE a=1;
12669**
12670** Changes within the local changeset are rebased as follows:
12671**
12672** <dl>
12673** <dt>Local INSERT<dd>
12674** This may only conflict with a remote INSERT. If the conflict
12675** resolution was OMIT, then add an UPDATE change to the rebased
12676** changeset. Or, if the conflict resolution was REPLACE, add
12677** nothing to the rebased changeset.
12678**
12679** <dt>Local DELETE<dd>
12680** This may conflict with a remote UPDATE or DELETE. In both cases the
12681** only possible resolution is OMIT. If the remote operation was a
12682** DELETE, then add no change to the rebased changeset. If the remote
12683** operation was an UPDATE, then the old.* fields of change are updated
12684** to reflect the new.* values in the UPDATE.
12685**
12686** <dt>Local UPDATE<dd>
12687** This may conflict with a remote UPDATE or DELETE. If it conflicts
12688** with a DELETE, and the conflict resolution was OMIT, then the update
12689** is changed into an INSERT. Any undefined values in the new.* record
12690** from the update change are filled in using the old.* values from
12691** the conflicting DELETE. Or, if the conflict resolution was REPLACE,
12692** the UPDATE change is simply omitted from the rebased changeset.
12693**
12694** If conflict is with a remote UPDATE and the resolution is OMIT, then
12695** the old.* values are rebased using the new.* values in the remote
12696** change. Or, if the resolution is REPLACE, then the change is copied
12697** into the rebased changeset with updates to columns also updated by
12698** the conflicting remote UPDATE removed. If this means no columns would
12699** be updated, the change is omitted.
12700** </dl>
12701**
12702** A local change may be rebased against multiple remote changes
12703** simultaneously. If a single key is modified by multiple remote
12704** changesets, they are combined as follows before the local changeset
12705** is rebased:
12706**
12707** <ul>
12708** <li> If there has been one or more REPLACE resolutions on a
12709** key, it is rebased according to a REPLACE.
12710**
12711** <li> If there have been no REPLACE resolutions on a key, then
12712** the local changeset is rebased according to the most recent
12713** of the OMIT resolutions.
12714** </ul>
12715**
12716** Note that conflict resolutions from multiple remote changesets are
12717** combined on a per-field basis, not per-row. This means that in the
12718** case of multiple remote UPDATE operations, some fields of a single
12719** local change may be rebased for REPLACE while others are rebased for
12720** OMIT.
12721**
12722** In order to rebase a local changeset, the remote changeset must first
12723** be applied to the local database using sqlite3changeset_apply_v2() and
12724** the buffer of rebase information captured. Then:
12725**
12726** <ol>
12727** <li> An sqlite3_rebaser object is created by calling
12728** sqlite3rebaser_create().
12729** <li> The new object is configured with the rebase buffer obtained from
12730** sqlite3changeset_apply_v2() by calling sqlite3rebaser_configure().
12731** If the local changeset is to be rebased against multiple remote
12732** changesets, then sqlite3rebaser_configure() should be called
12733** multiple times, in the same order that the multiple
12734** sqlite3changeset_apply_v2() calls were made.
12735** <li> Each local changeset is rebased by calling sqlite3rebaser_rebase().
12736** <li> The sqlite3_rebaser object is deleted by calling
12737** sqlite3rebaser_delete().
12738** </ol>
12739*/
12740typedef struct sqlite3_rebaser sqlite3_rebaser;
12741
12742/*
12743** CAPI3REF: Create a changeset rebaser object.
12744** EXPERIMENTAL
12745**
12746** Allocate a new changeset rebaser object. If successful, set (*ppNew) to
12747** point to the new object and return SQLITE_OK. Otherwise, if an error
12748** occurs, return an SQLite error code (e.g. SQLITE_NOMEM) and set (*ppNew)
12749** to NULL.
12750*/
12751SQLITE_API int sqlite3rebaser_create(sqlite3_rebaser **ppNew);
12752
12753/*
12754** CAPI3REF: Configure a changeset rebaser object.
12755** EXPERIMENTAL
12756**
12757** Configure the changeset rebaser object to rebase changesets according
12758** to the conflict resolutions described by buffer pRebase (size nRebase
12759** bytes), which must have been obtained from a previous call to
12760** sqlite3changeset_apply_v2().
12761*/
12762SQLITE_API int sqlite3rebaser_configure(
12763 sqlite3_rebaser*,
12764 int nRebase, const void *pRebase
12765);
12766
12767/*
12768** CAPI3REF: Rebase a changeset
12769** EXPERIMENTAL
12770**
12771** Argument pIn must point to a buffer containing a changeset nIn bytes
12772** in size. This function allocates and populates a buffer with a copy
12773** of the changeset rebased according to the configuration of the
12774** rebaser object passed as the first argument. If successful, (*ppOut)
12775** is set to point to the new buffer containing the rebased changeset and
12776** (*pnOut) to its size in bytes and SQLITE_OK returned. It is the
12777** responsibility of the caller to eventually free the new buffer using
12778** sqlite3_free(). Otherwise, if an error occurs, (*ppOut) and (*pnOut)
12779** are set to zero and an SQLite error code returned.
12780*/
12781SQLITE_API int sqlite3rebaser_rebase(
12782 sqlite3_rebaser*,
12783 int nIn, const void *pIn,
12784 int *pnOut, void **ppOut
12785);
12786
12787/*
12788** CAPI3REF: Delete a changeset rebaser object.
12789** EXPERIMENTAL
12790**
12791** Delete the changeset rebaser object and all associated resources. There
12792** should be one call to this function for each successful invocation
12793** of sqlite3rebaser_create().
12794*/
12795SQLITE_API void sqlite3rebaser_delete(sqlite3_rebaser *p);
12796
12797/*
12798** CAPI3REF: Streaming Versions of API functions.
12799**
12800** The six streaming API xxx_strm() functions serve similar purposes to the
12801** corresponding non-streaming API functions:
12802**
12803** <table border=1 style="margin-left:8ex;margin-right:8ex">
12804** <tr><th>Streaming function<th>Non-streaming equivalent</th>
12805** <tr><td>sqlite3changeset_apply_strm<td>[sqlite3changeset_apply]
12806** <tr><td>sqlite3changeset_apply_strm_v2<td>[sqlite3changeset_apply_v2]
12807** <tr><td>sqlite3changeset_concat_strm<td>[sqlite3changeset_concat]
12808** <tr><td>sqlite3changeset_invert_strm<td>[sqlite3changeset_invert]
12809** <tr><td>sqlite3changeset_start_strm<td>[sqlite3changeset_start]
12810** <tr><td>sqlite3session_changeset_strm<td>[sqlite3session_changeset]
12811** <tr><td>sqlite3session_patchset_strm<td>[sqlite3session_patchset]
12812** </table>
12813**
12814** Non-streaming functions that accept changesets (or patchsets) as input
12815** require that the entire changeset be stored in a single buffer in memory.
12816** Similarly, those that return a changeset or patchset do so by returning
12817** a pointer to a single large buffer allocated using sqlite3_malloc().
12818** Normally this is convenient. However, if an application running in a
12819** low-memory environment is required to handle very large changesets, the
12820** large contiguous memory allocations required can become onerous.
12821**
12822** In order to avoid this problem, instead of a single large buffer, input
12823** is passed to a streaming API functions by way of a callback function that
12824** the sessions module invokes to incrementally request input data as it is
12825** required. In all cases, a pair of API function parameters such as
12826**
12827** <pre>
12828** int nChangeset,
12829** void *pChangeset,
12830** </pre>
12831**
12832** Is replaced by:
12833**
12834** <pre>
12835** int (*xInput)(void *pIn, void *pData, int *pnData),
12836** void *pIn,
12837** </pre>
12838**
12839** Each time the xInput callback is invoked by the sessions module, the first
12840** argument passed is a copy of the supplied pIn context pointer. The second
12841** argument, pData, points to a buffer (*pnData) bytes in size. Assuming no
12842** error occurs the xInput method should copy up to (*pnData) bytes of data
12843** into the buffer and set (*pnData) to the actual number of bytes copied
12844** before returning SQLITE_OK. If the input is completely exhausted, (*pnData)
12845** should be set to zero to indicate this. Or, if an error occurs, an SQLite
12846** error code should be returned. In all cases, if an xInput callback returns
12847** an error, all processing is abandoned and the streaming API function
12848** returns a copy of the error code to the caller.
12849**
12850** In the case of sqlite3changeset_start_strm(), the xInput callback may be
12851** invoked by the sessions module at any point during the lifetime of the
12852** iterator. If such an xInput callback returns an error, the iterator enters
12853** an error state, whereby all subsequent calls to iterator functions
12854** immediately fail with the same error code as returned by xInput.
12855**
12856** Similarly, streaming API functions that return changesets (or patchsets)
12857** return them in chunks by way of a callback function instead of via a
12858** pointer to a single large buffer. In this case, a pair of parameters such
12859** as:
12860**
12861** <pre>
12862** int *pnChangeset,
12863** void **ppChangeset,
12864** </pre>
12865**
12866** Is replaced by:
12867**
12868** <pre>
12869** int (*xOutput)(void *pOut, const void *pData, int nData),
12870** void *pOut
12871** </pre>
12872**
12873** The xOutput callback is invoked zero or more times to return data to
12874** the application. The first parameter passed to each call is a copy of the
12875** pOut pointer supplied by the application. The second parameter, pData,
12876** points to a buffer nData bytes in size containing the chunk of output
12877** data being returned. If the xOutput callback successfully processes the
12878** supplied data, it should return SQLITE_OK to indicate success. Otherwise,
12879** it should return some other SQLite error code. In this case processing
12880** is immediately abandoned and the streaming API function returns a copy
12881** of the xOutput error code to the application.
12882**
12883** The sessions module never invokes an xOutput callback with the third
12884** parameter set to a value less than or equal to zero. Other than this,
12885** no guarantees are made as to the size of the chunks of data returned.
12886*/
12887SQLITE_API int sqlite3changeset_apply_strm(
12888 sqlite3 *db, /* Apply change to "main" db of this handle */
12889 int (*xInput)(void *pIn, void *pData, int *pnData), /* Input function */
12890 void *pIn, /* First arg for xInput */
12891 int(*xFilter)(
12892 void *pCtx, /* Copy of sixth arg to _apply() */
12893 const char *zTab /* Table name */
12894 ),
12895 int(*xConflict)(
12896 void *pCtx, /* Copy of sixth arg to _apply() */
12897 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */
12898 sqlite3_changeset_iter *p /* Handle describing change and conflict */
12899 ),
12900 void *pCtx /* First argument passed to xConflict */
12901);
12902SQLITE_API int sqlite3changeset_apply_v2_strm(
12903 sqlite3 *db, /* Apply change to "main" db of this handle */
12904 int (*xInput)(void *pIn, void *pData, int *pnData), /* Input function */
12905 void *pIn, /* First arg for xInput */
12906 int(*xFilter)(
12907 void *pCtx, /* Copy of sixth arg to _apply() */
12908 const char *zTab /* Table name */
12909 ),
12910 int(*xConflict)(
12911 void *pCtx, /* Copy of sixth arg to _apply() */
12912 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */
12913 sqlite3_changeset_iter *p /* Handle describing change and conflict */
12914 ),
12915 void *pCtx, /* First argument passed to xConflict */
12916 void **ppRebase, int *pnRebase,
12917 int flags
12918);
12919SQLITE_API int sqlite3changeset_concat_strm(
12920 int (*xInputA)(void *pIn, void *pData, int *pnData),
12921 void *pInA,
12922 int (*xInputB)(void *pIn, void *pData, int *pnData),
12923 void *pInB,
12924 int (*xOutput)(void *pOut, const void *pData, int nData),
12925 void *pOut
12926);
12927SQLITE_API int sqlite3changeset_invert_strm(
12928 int (*xInput)(void *pIn, void *pData, int *pnData),
12929 void *pIn,
12930 int (*xOutput)(void *pOut, const void *pData, int nData),
12931 void *pOut
12932);
12933SQLITE_API int sqlite3changeset_start_strm(
12934 sqlite3_changeset_iter **pp,
12935 int (*xInput)(void *pIn, void *pData, int *pnData),
12936 void *pIn
12937);
12938SQLITE_API int sqlite3changeset_start_v2_strm(
12939 sqlite3_changeset_iter **pp,
12940 int (*xInput)(void *pIn, void *pData, int *pnData),
12941 void *pIn,
12942 int flags
12943);
12944SQLITE_API int sqlite3session_changeset_strm(
12945 sqlite3_session *pSession,
12946 int (*xOutput)(void *pOut, const void *pData, int nData),
12947 void *pOut
12948);
12949SQLITE_API int sqlite3session_patchset_strm(
12950 sqlite3_session *pSession,
12951 int (*xOutput)(void *pOut, const void *pData, int nData),
12952 void *pOut
12953);
12954SQLITE_API int sqlite3changegroup_add_strm(sqlite3_changegroup*,
12955 int (*xInput)(void *pIn, void *pData, int *pnData),
12956 void *pIn
12957);
12958SQLITE_API int sqlite3changegroup_output_strm(sqlite3_changegroup*,
12959 int (*xOutput)(void *pOut, const void *pData, int nData),
12960 void *pOut
12961);
12962SQLITE_API int sqlite3rebaser_rebase_strm(
12963 sqlite3_rebaser *pRebaser,
12964 int (*xInput)(void *pIn, void *pData, int *pnData),
12965 void *pIn,
12966 int (*xOutput)(void *pOut, const void *pData, int nData),
12967 void *pOut
12968);
12969
12970/*
12971** CAPI3REF: Configure global parameters
12972**
12973** The sqlite3session_config() interface is used to make global configuration
12974** changes to the sessions module in order to tune it to the specific needs
12975** of the application.
12976**
12977** The sqlite3session_config() interface is not threadsafe. If it is invoked
12978** while any other thread is inside any other sessions method then the
12979** results are undefined. Furthermore, if it is invoked after any sessions
12980** related objects have been created, the results are also undefined.
12981**
12982** The first argument to the sqlite3session_config() function must be one
12983** of the SQLITE_SESSION_CONFIG_XXX constants defined below. The
12984** interpretation of the (void*) value passed as the second parameter and
12985** the effect of calling this function depends on the value of the first
12986** parameter.
12987**
12988** <dl>
12989** <dt>SQLITE_SESSION_CONFIG_STRMSIZE<dd>
12990** By default, the sessions module streaming interfaces attempt to input
12991** and output data in approximately 1 KiB chunks. This operand may be used
12992** to set and query the value of this configuration setting. The pointer
12993** passed as the second argument must point to a value of type (int).
12994** If this value is greater than 0, it is used as the new streaming data
12995** chunk size for both input and output. Before returning, the (int) value
12996** pointed to by pArg is set to the final value of the streaming interface
12997** chunk size.
12998** </dl>
12999**
13000** This function returns SQLITE_OK if successful, or an SQLite error code
13001** otherwise.
13002*/
13003SQLITE_API int sqlite3session_config(int op, void *pArg);
13004
13005/*
13006** CAPI3REF: Values for sqlite3session_config().
13007*/
13008#define SQLITE_SESSION_CONFIG_STRMSIZE 1
13009
13010/*
13011** Make sure we can call this stuff from C++.
13012*/
13013#ifdef __cplusplus
13014}
13015#endif
13016
13017#endif /* !defined(__SQLITESESSION_H_) && defined(SQLITE_ENABLE_SESSION) */
13018
13019/******** End of sqlite3session.h *********/
13020/******** Begin file fts5.h *********/
13021/*
13022** 2014 May 31
13023**
13024** The author disclaims copyright to this source code. In place of
13025** a legal notice, here is a blessing:
13026**
13027** May you do good and not evil.
13028** May you find forgiveness for yourself and forgive others.
13029** May you share freely, never taking more than you give.
13030**
13031******************************************************************************
13032**
13033** Interfaces to extend FTS5. Using the interfaces defined in this file,
13034** FTS5 may be extended with:
13035**
13036** * custom tokenizers, and
13037** * custom auxiliary functions.
13038*/
13039
13040
13041#ifndef _FTS5_H
13042#define _FTS5_H
13043
13044
13045#ifdef __cplusplus
13046extern "C" {
13047#endif
13048
13049/*************************************************************************
13050** CUSTOM AUXILIARY FUNCTIONS
13051**
13052** Virtual table implementations may overload SQL functions by implementing
13053** the sqlite3_module.xFindFunction() method.
13054*/
13055
13056typedef struct Fts5ExtensionApi Fts5ExtensionApi;
13057typedef struct Fts5Context Fts5Context;
13058typedef struct Fts5PhraseIter Fts5PhraseIter;
13059
13060typedef void (*fts5_extension_function)(
13061 const Fts5ExtensionApi *pApi, /* API offered by current FTS version */
13062 Fts5Context *pFts, /* First arg to pass to pApi functions */
13063 sqlite3_context *pCtx, /* Context for returning result/error */
13064 int nVal, /* Number of values in apVal[] array */
13065 sqlite3_value **apVal /* Array of trailing arguments */
13066);
13067
13068struct Fts5PhraseIter {
13069 const unsigned char *a;
13070 const unsigned char *b;
13071};
13072
13073/*
13074** EXTENSION API FUNCTIONS
13075**
13076** xUserData(pFts):
13077** Return a copy of the pUserData pointer passed to the xCreateFunction()
13078** API when the extension function was registered.
13079**
13080** xColumnTotalSize(pFts, iCol, pnToken):
13081** If parameter iCol is less than zero, set output variable *pnToken
13082** to the total number of tokens in the FTS5 table. Or, if iCol is
13083** non-negative but less than the number of columns in the table, return
13084** the total number of tokens in column iCol, considering all rows in
13085** the FTS5 table.
13086**
13087** If parameter iCol is greater than or equal to the number of columns
13088** in the table, SQLITE_RANGE is returned. Or, if an error occurs (e.g.
13089** an OOM condition or IO error), an appropriate SQLite error code is
13090** returned.
13091**
13092** xColumnCount(pFts):
13093** Return the number of columns in the table.
13094**
13095** xColumnSize(pFts, iCol, pnToken):
13096** If parameter iCol is less than zero, set output variable *pnToken
13097** to the total number of tokens in the current row. Or, if iCol is
13098** non-negative but less than the number of columns in the table, set
13099** *pnToken to the number of tokens in column iCol of the current row.
13100**
13101** If parameter iCol is greater than or equal to the number of columns
13102** in the table, SQLITE_RANGE is returned. Or, if an error occurs (e.g.
13103** an OOM condition or IO error), an appropriate SQLite error code is
13104** returned.
13105**
13106** This function may be quite inefficient if used with an FTS5 table
13107** created with the "columnsize=0" option.
13108**
13109** xColumnText:
13110** If parameter iCol is less than zero, or greater than or equal to the
13111** number of columns in the table, SQLITE_RANGE is returned.
13112**
13113** Otherwise, this function attempts to retrieve the text of column iCol of
13114** the current document. If successful, (*pz) is set to point to a buffer
13115** containing the text in utf-8 encoding, (*pn) is set to the size in bytes
13116** (not characters) of the buffer and SQLITE_OK is returned. Otherwise,
13117** if an error occurs, an SQLite error code is returned and the final values
13118** of (*pz) and (*pn) are undefined.
13119**
13120** xPhraseCount:
13121** Returns the number of phrases in the current query expression.
13122**
13123** xPhraseSize:
13124** If parameter iCol is less than zero, or greater than or equal to the
13125** number of phrases in the current query, as returned by xPhraseCount,
13126** 0 is returned. Otherwise, this function returns the number of tokens in
13127** phrase iPhrase of the query. Phrases are numbered starting from zero.
13128**
13129** xInstCount:
13130** Set *pnInst to the total number of occurrences of all phrases within
13131** the query within the current row. Return SQLITE_OK if successful, or
13132** an error code (i.e. SQLITE_NOMEM) if an error occurs.
13133**
13134** This API can be quite slow if used with an FTS5 table created with the
13135** "detail=none" or "detail=column" option. If the FTS5 table is created
13136** with either "detail=none" or "detail=column" and "content=" option
13137** (i.e. if it is a contentless table), then this API always returns 0.
13138**
13139** xInst:
13140** Query for the details of phrase match iIdx within the current row.
13141** Phrase matches are numbered starting from zero, so the iIdx argument
13142** should be greater than or equal to zero and smaller than the value
13143** output by xInstCount(). If iIdx is less than zero or greater than
13144** or equal to the value returned by xInstCount(), SQLITE_RANGE is returned.
13145**
13146** Otherwise, output parameter *piPhrase is set to the phrase number, *piCol
13147** to the column in which it occurs and *piOff the token offset of the
13148** first token of the phrase. SQLITE_OK is returned if successful, or an
13149** error code (i.e. SQLITE_NOMEM) if an error occurs.
13150**
13151** This API can be quite slow if used with an FTS5 table created with the
13152** "detail=none" or "detail=column" option.
13153**
13154** xRowid:
13155** Returns the rowid of the current row.
13156**
13157** xTokenize:
13158** Tokenize text using the tokenizer belonging to the FTS5 table.
13159**
13160** xQueryPhrase(pFts5, iPhrase, pUserData, xCallback):
13161** This API function is used to query the FTS table for phrase iPhrase
13162** of the current query. Specifically, a query equivalent to:
13163**
13164** ... FROM ftstable WHERE ftstable MATCH $p ORDER BY rowid
13165**
13166** with $p set to a phrase equivalent to the phrase iPhrase of the
13167** current query is executed. Any column filter that applies to
13168** phrase iPhrase of the current query is included in $p. For each
13169** row visited, the callback function passed as the fourth argument
13170** is invoked. The context and API objects passed to the callback
13171** function may be used to access the properties of each matched row.
13172** Invoking Api.xUserData() returns a copy of the pointer passed as
13173** the third argument to pUserData.
13174**
13175** If parameter iPhrase is less than zero, or greater than or equal to
13176** the number of phrases in the query, as returned by xPhraseCount(),
13177** this function returns SQLITE_RANGE.
13178**
13179** If the callback function returns any value other than SQLITE_OK, the
13180** query is abandoned and the xQueryPhrase function returns immediately.
13181** If the returned value is SQLITE_DONE, xQueryPhrase returns SQLITE_OK.
13182** Otherwise, the error code is propagated upwards.
13183**
13184** If the query runs to completion without incident, SQLITE_OK is returned.
13185** Or, if some error occurs before the query completes or is aborted by
13186** the callback, an SQLite error code is returned.
13187**
13188**
13189** xSetAuxdata(pFts5, pAux, xDelete)
13190**
13191** Save the pointer passed as the second argument as the extension function's
13192** "auxiliary data". The pointer may then be retrieved by the current or any
13193** future invocation of the same fts5 extension function made as part of
13194** the same MATCH query using the xGetAuxdata() API.
13195**
13196** Each extension function is allocated a single auxiliary data slot for
13197** each FTS query (MATCH expression). If the extension function is invoked
13198** more than once for a single FTS query, then all invocations share a
13199** single auxiliary data context.
13200**
13201** If there is already an auxiliary data pointer when this function is
13202** invoked, then it is replaced by the new pointer. If an xDelete callback
13203** was specified along with the original pointer, it is invoked at this
13204** point.
13205**
13206** The xDelete callback, if one is specified, is also invoked on the
13207** auxiliary data pointer after the FTS5 query has finished.
13208**
13209** If an error (e.g. an OOM condition) occurs within this function,
13210** the auxiliary data is set to NULL and an error code returned. If the
13211** xDelete parameter was not NULL, it is invoked on the auxiliary data
13212** pointer before returning.
13213**
13214**
13215** xGetAuxdata(pFts5, bClear)
13216**
13217** Returns the current auxiliary data pointer for the fts5 extension
13218** function. See the xSetAuxdata() method for details.
13219**
13220** If the bClear argument is non-zero, then the auxiliary data is cleared
13221** (set to NULL) before this function returns. In this case the xDelete,
13222** if any, is not invoked.
13223**
13224**
13225** xRowCount(pFts5, pnRow)
13226**
13227** This function is used to retrieve the total number of rows in the table.
13228** In other words, the same value that would be returned by:
13229**
13230** SELECT count(*) FROM ftstable;
13231**
13232** xPhraseFirst()
13233** This function is used, along with type Fts5PhraseIter and the xPhraseNext
13234** method, to iterate through all instances of a single query phrase within
13235** the current row. This is the same information as is accessible via the
13236** xInstCount/xInst APIs. While the xInstCount/xInst APIs are more convenient
13237** to use, this API may be faster under some circumstances. To iterate
13238** through instances of phrase iPhrase, use the following code:
13239**
13240** Fts5PhraseIter iter;
13241** int iCol, iOff;
13242** for(pApi->xPhraseFirst(pFts, iPhrase, &iter, &iCol, &iOff);
13243** iCol>=0;
13244** pApi->xPhraseNext(pFts, &iter, &iCol, &iOff)
13245** ){
13246** // An instance of phrase iPhrase at offset iOff of column iCol
13247** }
13248**
13249** The Fts5PhraseIter structure is defined above. Applications should not
13250** modify this structure directly - it should only be used as shown above
13251** with the xPhraseFirst() and xPhraseNext() API methods (and by
13252** xPhraseFirstColumn() and xPhraseNextColumn() as illustrated below).
13253**
13254** This API can be quite slow if used with an FTS5 table created with the
13255** "detail=none" or "detail=column" option. If the FTS5 table is created
13256** with either "detail=none" or "detail=column" and "content=" option
13257** (i.e. if it is a contentless table), then this API always iterates
13258** through an empty set (all calls to xPhraseFirst() set iCol to -1).
13259**
13260** In all cases, matches are visited in (column ASC, offset ASC) order.
13261** i.e. all those in column 0, sorted by offset, followed by those in
13262** column 1, etc.
13263**
13264** xPhraseNext()
13265** See xPhraseFirst above.
13266**
13267** xPhraseFirstColumn()
13268** This function and xPhraseNextColumn() are similar to the xPhraseFirst()
13269** and xPhraseNext() APIs described above. The difference is that instead
13270** of iterating through all instances of a phrase in the current row, these
13271** APIs are used to iterate through the set of columns in the current row
13272** that contain one or more instances of a specified phrase. For example:
13273**
13274** Fts5PhraseIter iter;
13275** int iCol;
13276** for(pApi->xPhraseFirstColumn(pFts, iPhrase, &iter, &iCol);
13277** iCol>=0;
13278** pApi->xPhraseNextColumn(pFts, &iter, &iCol)
13279** ){
13280** // Column iCol contains at least one instance of phrase iPhrase
13281** }
13282**
13283** This API can be quite slow if used with an FTS5 table created with the
13284** "detail=none" option. If the FTS5 table is created with either
13285** "detail=none" "content=" option (i.e. if it is a contentless table),
13286** then this API always iterates through an empty set (all calls to
13287** xPhraseFirstColumn() set iCol to -1).
13288**
13289** The information accessed using this API and its companion
13290** xPhraseFirstColumn() may also be obtained using xPhraseFirst/xPhraseNext
13291** (or xInst/xInstCount). The chief advantage of this API is that it is
13292** significantly more efficient than those alternatives when used with
13293** "detail=column" tables.
13294**
13295** xPhraseNextColumn()
13296** See xPhraseFirstColumn above.
13297**
13298** xQueryToken(pFts5, iPhrase, iToken, ppToken, pnToken)
13299** This is used to access token iToken of phrase iPhrase of the current
13300** query. Before returning, output parameter *ppToken is set to point
13301** to a buffer containing the requested token, and *pnToken to the
13302** size of this buffer in bytes.
13303**
13304** If iPhrase or iToken are less than zero, or if iPhrase is greater than
13305** or equal to the number of phrases in the query as reported by
13306** xPhraseCount(), or if iToken is equal to or greater than the number of
13307** tokens in the phrase, SQLITE_RANGE is returned and *ppToken and *pnToken
13308 are both zeroed.
13309**
13310** The output text is not a copy of the query text that specified the
13311** token. It is the output of the tokenizer module. For tokendata=1
13312** tables, this includes any embedded 0x00 and trailing data.
13313**
13314** xInstToken(pFts5, iIdx, iToken, ppToken, pnToken)
13315** This is used to access token iToken of phrase hit iIdx within the
13316** current row. If iIdx is less than zero or greater than or equal to the
13317** value returned by xInstCount(), SQLITE_RANGE is returned. Otherwise,
13318** output variable (*ppToken) is set to point to a buffer containing the
13319** matching document token, and (*pnToken) to the size of that buffer in
13320** bytes.
13321**
13322** The output text is not a copy of the document text that was tokenized.
13323** It is the output of the tokenizer module. For tokendata=1 tables, this
13324** includes any embedded 0x00 and trailing data.
13325**
13326** This API may be slow in some cases if the token identified by parameters
13327** iIdx and iToken matched a prefix token in the query. In most cases, the
13328** first call to this API for each prefix token in the query is forced
13329** to scan the portion of the full-text index that matches the prefix
13330** token to collect the extra data required by this API. If the prefix
13331** token matches a large number of token instances in the document set,
13332** this may be a performance problem.
13333**
13334** If the user knows in advance that a query may use this API for a
13335** prefix token, FTS5 may be configured to collect all required data as part
13336** of the initial querying of the full-text index, avoiding the second scan
13337** entirely. This also causes prefix queries that do not use this API to
13338** run more slowly and use more memory. FTS5 may be configured in this way
13339** either on a per-table basis using the [FTS5 insttoken | 'insttoken']
13340** option, or on a per-query basis using the
13341** [fts5_insttoken | fts5_insttoken()] user function.
13342**
13343** This API can be quite slow if used with an FTS5 table created with the
13344** "detail=none" or "detail=column" option.
13345**
13346** xColumnLocale(pFts5, iIdx, pzLocale, pnLocale)
13347** If parameter iCol is less than zero, or greater than or equal to the
13348** number of columns in the table, SQLITE_RANGE is returned.
13349**
13350** Otherwise, this function attempts to retrieve the locale associated
13351** with column iCol of the current row. Usually, there is no associated
13352** locale, and output parameters (*pzLocale) and (*pnLocale) are set
13353** to NULL and 0, respectively. However, if the fts5_locale() function
13354** was used to associate a locale with the value when it was inserted
13355** into the fts5 table, then (*pzLocale) is set to point to a nul-terminated
13356** buffer containing the name of the locale in utf-8 encoding. (*pnLocale)
13357** is set to the size in bytes of the buffer, not including the
13358** nul-terminator.
13359**
13360** If successful, SQLITE_OK is returned. Or, if an error occurs, an
13361** SQLite error code is returned. The final value of the output parameters
13362** is undefined in this case.
13363**
13364** xTokenize_v2:
13365** Tokenize text using the tokenizer belonging to the FTS5 table. This
13366** API is the same as the xTokenize() API, except that it allows a tokenizer
13367** locale to be specified.
13368*/
13369struct Fts5ExtensionApi {
13370 int iVersion; /* Currently always set to 4 */
13371
13372 void *(*xUserData)(Fts5Context*);
13373
13374 int (*xColumnCount)(Fts5Context*);
13375 int (*xRowCount)(Fts5Context*, sqlite3_int64 *pnRow);
13376 int (*xColumnTotalSize)(Fts5Context*, int iCol, sqlite3_int64 *pnToken);
13377
13378 int (*xTokenize)(Fts5Context*,
13379 const char *pText, int nText, /* Text to tokenize */
13380 void *pCtx, /* Context passed to xToken() */
13381 int (*xToken)(void*, int, const char*, int, int, int) /* Callback */
13382 );
13383
13384 int (*xPhraseCount)(Fts5Context*);
13385 int (*xPhraseSize)(Fts5Context*, int iPhrase);
13386
13387 int (*xInstCount)(Fts5Context*, int *pnInst);
13388 int (*xInst)(Fts5Context*, int iIdx, int *piPhrase, int *piCol, int *piOff);
13389
13390 sqlite3_int64 (*xRowid)(Fts5Context*);
13391 int (*xColumnText)(Fts5Context*, int iCol, const char **pz, int *pn);
13392 int (*xColumnSize)(Fts5Context*, int iCol, int *pnToken);
13393
13394 int (*xQueryPhrase)(Fts5Context*, int iPhrase, void *pUserData,
13395 int(*)(const Fts5ExtensionApi*,Fts5Context*,void*)
13396 );
13397 int (*xSetAuxdata)(Fts5Context*, void *pAux, void(*xDelete)(void*));
13398 void *(*xGetAuxdata)(Fts5Context*, int bClear);
13399
13400 int (*xPhraseFirst)(Fts5Context*, int iPhrase, Fts5PhraseIter*, int*, int*);
13401 void (*xPhraseNext)(Fts5Context*, Fts5PhraseIter*, int *piCol, int *piOff);
13402
13403 int (*xPhraseFirstColumn)(Fts5Context*, int iPhrase, Fts5PhraseIter*, int*);
13404 void (*xPhraseNextColumn)(Fts5Context*, Fts5PhraseIter*, int *piCol);
13405
13406 /* Below this point are iVersion>=3 only */
13407 int (*xQueryToken)(Fts5Context*,
13408 int iPhrase, int iToken,
13409 const char **ppToken, int *pnToken
13410 );
13411 int (*xInstToken)(Fts5Context*, int iIdx, int iToken, const char**, int*);
13412
13413 /* Below this point are iVersion>=4 only */
13414 int (*xColumnLocale)(Fts5Context*, int iCol, const char **pz, int *pn);
13415 int (*xTokenize_v2)(Fts5Context*,
13416 const char *pText, int nText, /* Text to tokenize */
13417 const char *pLocale, int nLocale, /* Locale to pass to tokenizer */
13418 void *pCtx, /* Context passed to xToken() */
13419 int (*xToken)(void*, int, const char*, int, int, int) /* Callback */
13420 );
13421};
13422
13423/*
13424** CUSTOM AUXILIARY FUNCTIONS
13425*************************************************************************/
13426
13427/*************************************************************************
13428** CUSTOM TOKENIZERS
13429**
13430** Applications may also register custom tokenizer types. A tokenizer
13431** is registered by providing fts5 with a populated instance of the
13432** following structure. All structure methods must be defined, setting
13433** any member of the fts5_tokenizer struct to NULL leads to undefined
13434** behaviour. The structure methods are expected to function as follows:
13435**
13436** xCreate:
13437** This function is used to allocate and initialize a tokenizer instance.
13438** A tokenizer instance is required to actually tokenize text.
13439**
13440** The first argument passed to this function is a copy of the (void*)
13441** pointer provided by the application when the fts5_tokenizer_v2 object
13442** was registered with FTS5 (the third argument to xCreateTokenizer()).
13443** The second and third arguments are an array of nul-terminated strings
13444** containing the tokenizer arguments, if any, specified following the
13445** tokenizer name as part of the CREATE VIRTUAL TABLE statement used
13446** to create the FTS5 table.
13447**
13448** The final argument is an output variable. If successful, (*ppOut)
13449** should be set to point to the new tokenizer handle and SQLITE_OK
13450** returned. If an error occurs, some value other than SQLITE_OK should
13451** be returned. In this case, fts5 assumes that the final value of *ppOut
13452** is undefined.
13453**
13454** xDelete:
13455** This function is invoked to delete a tokenizer handle previously
13456** allocated using xCreate(). Fts5 guarantees that this function will
13457** be invoked exactly once for each successful call to xCreate().
13458**
13459** xTokenize:
13460** This function is expected to tokenize the nText byte string indicated
13461** by argument pText. pText may or may not be nul-terminated. The first
13462** argument passed to this function is a pointer to an Fts5Tokenizer object
13463** returned by an earlier call to xCreate().
13464**
13465** The third argument indicates the reason that FTS5 is requesting
13466** tokenization of the supplied text. This is always one of the following
13467** four values:
13468**
13469** <ul><li> <b>FTS5_TOKENIZE_DOCUMENT</b> - A document is being inserted into
13470** or removed from the FTS table. The tokenizer is being invoked to
13471** determine the set of tokens to add to (or delete from) the
13472** FTS index.
13473**
13474** <li> <b>FTS5_TOKENIZE_QUERY</b> - A MATCH query is being executed
13475** against the FTS index. The tokenizer is being called to tokenize
13476** a bareword or quoted string specified as part of the query.
13477**
13478** <li> <b>(FTS5_TOKENIZE_QUERY | FTS5_TOKENIZE_PREFIX)</b> - Same as
13479** FTS5_TOKENIZE_QUERY, except that the bareword or quoted string is
13480** followed by a "*" character, indicating that the last token
13481** returned by the tokenizer will be treated as a token prefix.
13482**
13483** <li> <b>FTS5_TOKENIZE_AUX</b> - The tokenizer is being invoked to
13484** satisfy an fts5_api.xTokenize() request made by an auxiliary
13485** function. Or an fts5_api.xColumnSize() request made by the same
13486** on a columnsize=0 database.
13487** </ul>
13488**
13489** The sixth and seventh arguments passed to xTokenize() - pLocale and
13490** nLocale - are a pointer to a buffer containing the locale to use for
13491** tokenization (e.g. "en_US") and its size in bytes, respectively. The
13492** pLocale buffer is not nul-terminated. pLocale may be passed NULL (in
13493** which case nLocale is always 0) to indicate that the tokenizer should
13494** use its default locale.
13495**
13496** For each token in the input string, the supplied callback xToken() must
13497** be invoked. The first argument to it should be a copy of the pointer
13498** passed as the second argument to xTokenize(). The third and fourth
13499** arguments are a pointer to a buffer containing the token text, and the
13500** size of the token in bytes. The 4th and 5th arguments are the byte offsets
13501** of the first byte of and first byte immediately following the text from
13502** which the token is derived within the input.
13503**
13504** The second argument passed to the xToken() callback ("tflags") should
13505** normally be set to 0. The exception is if the tokenizer supports
13506** synonyms. In this case see the discussion below for details.
13507**
13508** FTS5 assumes the xToken() callback is invoked for each token in the
13509** order that they occur within the input text.
13510**
13511** If an xToken() callback returns any value other than SQLITE_OK, then
13512** the tokenization should be abandoned and the xTokenize() method should
13513** immediately return a copy of the xToken() return value. Or, if the
13514** input buffer is exhausted, xTokenize() should return SQLITE_OK. Finally,
13515** if an error occurs with the xTokenize() implementation itself, it
13516** may abandon the tokenization and return any error code other than
13517** SQLITE_OK or SQLITE_DONE.
13518**
13519** If the tokenizer is registered using an fts5_tokenizer_v2 object,
13520** then the xTokenize() method has two additional arguments - pLocale
13521** and nLocale. These specify the locale that the tokenizer should use
13522** for the current request. If pLocale and nLocale are both 0, then the
13523** tokenizer should use its default locale. Otherwise, pLocale points to
13524** an nLocale byte buffer containing the name of the locale to use as utf-8
13525** text. pLocale is not nul-terminated.
13526**
13527** FTS5_TOKENIZER
13528**
13529** There is also an fts5_tokenizer object. This is an older, deprecated,
13530** version of fts5_tokenizer_v2. It is similar except that:
13531**
13532** <ul>
13533** <li> There is no "iVersion" field, and
13534** <li> The xTokenize() method does not take a locale argument.
13535** </ul>
13536**
13537** Legacy fts5_tokenizer tokenizers must be registered using the
13538** legacy xCreateTokenizer() function, instead of xCreateTokenizer_v2().
13539**
13540** Tokenizer implementations registered using either API may be retrieved
13541** using both xFindTokenizer() and xFindTokenizer_v2().
13542**
13543** SYNONYM SUPPORT
13544**
13545** Custom tokenizers may also support synonyms. Consider a case in which a
13546** user wishes to query for a phrase such as "first place". Using the
13547** built-in tokenizers, the FTS5 query 'first + place' will match instances
13548** of "first place" within the document set, but not alternative forms
13549** such as "1st place". In some applications, it would be better to match
13550** all instances of "first place" or "1st place" regardless of which form
13551** the user specified in the MATCH query text.
13552**
13553** There are several ways to approach this in FTS5:
13554**
13555** <ol><li> By mapping all synonyms to a single token. In this case, using
13556** the above example, this means that the tokenizer returns the
13557** same token for inputs "first" and "1st". Say that token is in
13558** fact "first", so that when the user inserts the document "I won
13559** 1st place" entries are added to the index for tokens "i", "won",
13560** "first" and "place". If the user then queries for '1st + place',
13561** the tokenizer substitutes "first" for "1st" and the query works
13562** as expected.
13563**
13564** <li> By querying the index for all synonyms of each query term
13565** separately. In this case, when tokenizing query text, the
13566** tokenizer may provide multiple synonyms for a single term
13567** within the document. FTS5 then queries the index for each
13568** synonym individually. For example, faced with the query:
13569**
13570** <codeblock>
13571** ... MATCH 'first place'</codeblock>
13572**
13573** the tokenizer offers both "1st" and "first" as synonyms for the
13574** first token in the MATCH query and FTS5 effectively runs a query
13575** similar to:
13576**
13577** <codeblock>
13578** ... MATCH '(first OR 1st) place'</codeblock>
13579**
13580** except that, for the purposes of auxiliary functions, the query
13581** still appears to contain just two phrases - "(first OR 1st)"
13582** being treated as a single phrase.
13583**
13584** <li> By adding multiple synonyms for a single term to the FTS index.
13585** Using this method, when tokenizing document text, the tokenizer
13586** provides multiple synonyms for each token. So that when a
13587** document such as "I won first place" is tokenized, entries are
13588** added to the FTS index for "i", "won", "first", "1st" and
13589** "place".
13590**
13591** This way, even if the tokenizer does not provide synonyms
13592** when tokenizing query text (it should not - to do so would be
13593** inefficient), it doesn't matter if the user queries for
13594** 'first + place' or '1st + place', as there are entries in the
13595** FTS index corresponding to both forms of the first token.
13596** </ol>
13597**
13598** Whether it is parsing document or query text, any call to xToken that
13599** specifies a <i>tflags</i> argument with the FTS5_TOKEN_COLOCATED bit
13600** is considered to supply a synonym for the previous token. For example,
13601** when parsing the document "I won first place", a tokenizer that supports
13602** synonyms would call xToken() 5 times, as follows:
13603**
13604** <codeblock>
13605** xToken(pCtx, 0, "i", 1, 0, 1);
13606** xToken(pCtx, 0, "won", 3, 2, 5);
13607** xToken(pCtx, 0, "first", 5, 6, 11);
13608** xToken(pCtx, FTS5_TOKEN_COLOCATED, "1st", 3, 6, 11);
13609** xToken(pCtx, 0, "place", 5, 12, 17);
13610**</codeblock>
13611**
13612** It is an error to specify the FTS5_TOKEN_COLOCATED flag the first time
13613** xToken() is called. Multiple synonyms may be specified for a single token
13614** by making multiple calls to xToken(FTS5_TOKEN_COLOCATED) in sequence.
13615** There is no limit to the number of synonyms that may be provided for a
13616** single token.
13617**
13618** In many cases, method (1) above is the best approach. It does not add
13619** extra data to the FTS index or require FTS5 to query for multiple terms,
13620** so it is efficient in terms of disk space and query speed. However, it
13621** does not support prefix queries very well. If, as suggested above, the
13622** token "first" is substituted for "1st" by the tokenizer, then the query:
13623**
13624** <codeblock>
13625** ... MATCH '1s*'</codeblock>
13626**
13627** will not match documents that contain the token "1st" (as the tokenizer
13628** will probably not map "1s" to any prefix of "first").
13629**
13630** For full prefix support, method (3) may be preferred. In this case,
13631** because the index contains entries for both "first" and "1st", prefix
13632** queries such as 'fi*' or '1s*' will match correctly. However, because
13633** extra entries are added to the FTS index, this method uses more space
13634** within the database.
13635**
13636** Method (2) offers a midpoint between (1) and (3). Using this method,
13637** a query such as '1s*' will match documents that contain the literal
13638** token "1st", but not "first" (assuming the tokenizer is not able to
13639** provide synonyms for prefixes). However, a non-prefix query like '1st'
13640** will match against "1st" and "first". This method does not require
13641** extra disk space, as no extra entries are added to the FTS index.
13642** On the other hand, it may require more CPU cycles to run MATCH queries,
13643** as separate queries of the FTS index are required for each synonym.
13644**
13645** When using methods (2) or (3), it is important that the tokenizer only
13646** provide synonyms when tokenizing document text (method (3)) or query
13647** text (method (2)), not both. Doing so will not cause any errors, but is
13648** inefficient.
13649*/
13650typedef struct Fts5Tokenizer Fts5Tokenizer;
13651typedef struct fts5_tokenizer_v2 fts5_tokenizer_v2;
13652struct fts5_tokenizer_v2 {
13653 int iVersion; /* Currently always 2 */
13654
13655 int (*xCreate)(void*, const char **azArg, int nArg, Fts5Tokenizer **ppOut);
13656 void (*xDelete)(Fts5Tokenizer*);
13657 int (*xTokenize)(Fts5Tokenizer*,
13658 void *pCtx,
13659 int flags, /* Mask of FTS5_TOKENIZE_* flags */
13660 const char *pText, int nText,
13661 const char *pLocale, int nLocale,
13662 int (*xToken)(
13663 void *pCtx, /* Copy of 2nd argument to xTokenize() */
13664 int tflags, /* Mask of FTS5_TOKEN_* flags */
13665 const char *pToken, /* Pointer to buffer containing token */
13666 int nToken, /* Size of token in bytes */
13667 int iStart, /* Byte offset of token within input text */
13668 int iEnd /* Byte offset of end of token within input text */
13669 )
13670 );
13671};
13672
13673/*
13674** New code should use the fts5_tokenizer_v2 type to define tokenizer
13675** implementations. The following type is included for legacy applications
13676** that still use it.
13677*/
13678typedef struct fts5_tokenizer fts5_tokenizer;
13679struct fts5_tokenizer {
13680 int (*xCreate)(void*, const char **azArg, int nArg, Fts5Tokenizer **ppOut);
13681 void (*xDelete)(Fts5Tokenizer*);
13682 int (*xTokenize)(Fts5Tokenizer*,
13683 void *pCtx,
13684 int flags, /* Mask of FTS5_TOKENIZE_* flags */
13685 const char *pText, int nText,
13686 int (*xToken)(
13687 void *pCtx, /* Copy of 2nd argument to xTokenize() */
13688 int tflags, /* Mask of FTS5_TOKEN_* flags */
13689 const char *pToken, /* Pointer to buffer containing token */
13690 int nToken, /* Size of token in bytes */
13691 int iStart, /* Byte offset of token within input text */
13692 int iEnd /* Byte offset of end of token within input text */
13693 )
13694 );
13695};
13696
13697
13698/* Flags that may be passed as the third argument to xTokenize() */
13699#define FTS5_TOKENIZE_QUERY 0x0001
13700#define FTS5_TOKENIZE_PREFIX 0x0002
13701#define FTS5_TOKENIZE_DOCUMENT 0x0004
13702#define FTS5_TOKENIZE_AUX 0x0008
13703
13704/* Flags that may be passed by the tokenizer implementation back to FTS5
13705** as the third argument to the supplied xToken callback. */
13706#define FTS5_TOKEN_COLOCATED 0x0001 /* Same position as prev. token */
13707
13708/*
13709** END OF CUSTOM TOKENIZERS
13710*************************************************************************/
13711
13712/*************************************************************************
13713** FTS5 EXTENSION REGISTRATION API
13714*/
13715typedef struct fts5_api fts5_api;
13716struct fts5_api {
13717 int iVersion; /* Currently always set to 3 */
13718
13719 /* Create a new tokenizer */
13720 int (*xCreateTokenizer)(
13721 fts5_api *pApi,
13722 const char *zName,
13723 void *pUserData,
13724 fts5_tokenizer *pTokenizer,
13725 void (*xDestroy)(void*)
13726 );
13727
13728 /* Find an existing tokenizer */
13729 int (*xFindTokenizer)(
13730 fts5_api *pApi,
13731 const char *zName,
13732 void **ppUserData,
13733 fts5_tokenizer *pTokenizer
13734 );
13735
13736 /* Create a new auxiliary function */
13737 int (*xCreateFunction)(
13738 fts5_api *pApi,
13739 const char *zName,
13740 void *pUserData,
13741 fts5_extension_function xFunction,
13742 void (*xDestroy)(void*)
13743 );
13744
13745 /* APIs below this point are only available if iVersion>=3 */
13746
13747 /* Create a new tokenizer */
13748 int (*xCreateTokenizer_v2)(
13749 fts5_api *pApi,
13750 const char *zName,
13751 void *pUserData,
13752 fts5_tokenizer_v2 *pTokenizer,
13753 void (*xDestroy)(void*)
13754 );
13755
13756 /* Find an existing tokenizer */
13757 int (*xFindTokenizer_v2)(
13758 fts5_api *pApi,
13759 const char *zName,
13760 void **ppUserData,
13761 fts5_tokenizer_v2 **ppTokenizer
13762 );
13763};
13764
13765/*
13766** END OF REGISTRATION API
13767*************************************************************************/
13768
13769#ifdef __cplusplus
13770} /* end of the 'extern "C"' block */
13771#endif
13772
13773#endif /* _FTS5_H */
13774
13775/******** End of fts5.h *********/
13776#endif /* SQLITE3_H */
13777#else // USE_LIBSQLITE3
13778 // If users really want to link against the system sqlite3 we
13779// need to make this file a noop.
13780 #endif